diff --git a/app/Actions/User/CreateUser.php b/app/Actions/User/CreateUser.php
index ead5eca0..d54e5a4f 100644
--- a/app/Actions/User/CreateUser.php
+++ b/app/Actions/User/CreateUser.php
@@ -17,11 +17,11 @@ class CreateUser
 {
     /**
      * @param  array{name: string, email: string, password?: string, google_id?: string, github_id?: string, email_verified_at?: \DateTimeInterface|null, is_invite?: bool, registration_ip?: string|null}  $data
-     * @param  array<string, string>  $utmParameters
+     * @param  array<string, string>  $attributionParameters  UTM parameters and ad click IDs (gclid, fbclid, etc.) captured before signup
      */
-    public static function execute(array $data, array $utmParameters = []): User
+    public static function execute(array $data, array $attributionParameters = []): User
     {
-        $user = DB::transaction(function () use ($data, $utmParameters): User {
+        $user = DB::transaction(function () use ($data, $attributionParameters): User {
             $isInviteRegistration = data_get($data, 'is_invite', false);
             $requiresCardForTrial = (bool) config('trypost.billing.require_card_for_trial', true);
             $accountAttributes = [
@@ -45,7 +45,7 @@ public static function execute(array $data, array $utmParameters = []): User
                 'email_verified_at' => data_get($data, 'email_verified_at', $isInviteRegistration ? now() : null),
                 'account_id' => $account->id,
                 'registration_ip' => data_get($data, 'registration_ip'),
-            ], $utmParameters));
+            ], $attributionParameters));
 
             $account->update(['owner_id' => $user->id]);
 
diff --git a/app/Http/Controllers/Auth/Concerns/PreservesAttributionParameters.php b/app/Http/Controllers/Auth/Concerns/PreservesAttributionParameters.php
new file mode 100644
index 00000000..27e2f1cf
--- /dev/null
+++ b/app/Http/Controllers/Auth/Concerns/PreservesAttributionParameters.php
@@ -0,0 +1,50 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Http\Controllers\Auth\Concerns;
+
+use App\Support\AttributionKeys;
+use Illuminate\Http\Request;
+use Illuminate\Support\Str;
+
+trait PreservesAttributionParameters
+{
+    /**
+     * UTM values are ours (our own campaign URLs), so truncating them to a
+     * safe length is fine. Click IDs are opaque tokens assigned by the ad
+     * platform — Google explicitly warns never to truncate or assume a
+     * fixed max length for gclid, since it has already grown over time. The
+     * `gclid`/etc. columns are `text`, so there's no need to cap them here.
+     *
+     * A key present with an empty value (e.g. `?utm_source=&gclid=`, which
+     * some ad/email templates always append) is filtered out along with
+     * absent keys, so it never overwrites a null column with `''`.
+     *
+     * @return array<string, string>
+     */
+    private function extractAttributionParameters(Request $request): array
+    {
+        $utm = collect($request->only(AttributionKeys::UTM))
+            ->filter(fn ($value) => is_string($value))
+            ->map(fn (string $value) => Str::limit($value, 255, ''));
+
+        $clickIds = collect($request->only(AttributionKeys::CLICK_ID))
+            ->filter(fn ($value) => is_string($value));
+
+        return $utm->merge($clickIds)->filter()->all();
+    }
+
+    private function storeAttributionParameters(Request $request): void
+    {
+        $request->session()->put('attribution_parameters', $this->extractAttributionParameters($request));
+    }
+
+    /**
+     * @return array<string, string>
+     */
+    private function retrieveAttributionParameters(): array
+    {
+        return session()->pull('attribution_parameters', []);
+    }
+}
diff --git a/app/Http/Controllers/Auth/Concerns/PreservesUtmParameters.php b/app/Http/Controllers/Auth/Concerns/PreservesUtmParameters.php
deleted file mode 100644
index 90b174c4..00000000
--- a/app/Http/Controllers/Auth/Concerns/PreservesUtmParameters.php
+++ /dev/null
@@ -1,48 +0,0 @@
-<?php
-
-declare(strict_types=1);
-
-namespace App\Http\Controllers\Auth\Concerns;
-
-use Illuminate\Http\Request;
-
-trait PreservesUtmParameters
-{
-    private const array UTM_KEYS = [
-        'utm_source',
-        'utm_medium',
-        'utm_campaign',
-        'utm_term',
-        'utm_content',
-    ];
-
-    /**
-     * @return array<string, string>
-     */
-    private function extractUtmParameters(Request $request): array
-    {
-        return array_filter(
-            array_map(
-                fn (string $value) => mb_substr($value, 0, 255),
-                array_filter($request->only(self::UTM_KEYS), 'is_string'),
-            ),
-        );
-    }
-
-    private function storeUtmParameters(Request $request): void
-    {
-        $utms = $this->extractUtmParameters($request);
-
-        if ($utms !== []) {
-            $request->session()->put('utm_parameters', $utms);
-        }
-    }
-
-    /**
-     * @return array<string, string>
-     */
-    private function retrieveUtmParameters(): array
-    {
-        return session()->pull('utm_parameters', []);
-    }
-}
diff --git a/app/Http/Controllers/Auth/GitHubController.php b/app/Http/Controllers/Auth/GitHubController.php
index 3b3f09ba..5b11104d 100644
--- a/app/Http/Controllers/Auth/GitHubController.php
+++ b/app/Http/Controllers/Auth/GitHubController.php
@@ -5,7 +5,7 @@
 namespace App\Http\Controllers\Auth;
 
 use App\Actions\User\CreateUser;
-use App\Http\Controllers\Auth\Concerns\PreservesUtmParameters;
+use App\Http\Controllers\Auth\Concerns\PreservesAttributionParameters;
 use App\Http\Controllers\Controller;
 use App\Models\User;
 use Illuminate\Auth\Events\Registered;
@@ -16,11 +16,11 @@
 
 class GitHubController extends Controller
 {
-    use PreservesUtmParameters;
+    use PreservesAttributionParameters;
 
     public function redirect(Request $request): RedirectResponse
     {
-        $this->storeUtmParameters($request);
+        $this->storeAttributionParameters($request);
 
         return Socialite::driver('github')
             ->scopes(['read:user', 'user:email'])
@@ -90,14 +90,14 @@ private function loginExistingUser(User $user, string $githubId): RedirectRespon
 
         Auth::login($user, remember: true);
 
-        $this->retrieveUtmParameters();
+        $this->retrieveAttributionParameters();
 
         return redirect()->route('app.home');
     }
 
     private function registerNewUser(\Laravel\Socialite\Contracts\User $githubUser): RedirectResponse
     {
-        $utmParameters = $this->retrieveUtmParameters();
+        $attributionParameters = $this->retrieveAttributionParameters();
 
         $user = CreateUser::execute([
             'name' => $githubUser->getName() ?? $githubUser->getNickname() ?? explode('@', $githubUser->getEmail())[0],
@@ -105,7 +105,7 @@ private function registerNewUser(\Laravel\Socialite\Contracts\User $githubUser):
             'github_id' => (string) $githubUser->getId(),
             'email_verified_at' => now(),
             'registration_ip' => request()->ip(),
-        ], $utmParameters);
+        ], $attributionParameters);
 
         event(new Registered($user));
 
@@ -113,6 +113,6 @@ private function registerNewUser(\Laravel\Socialite\Contracts\User $githubUser):
 
         session()->flash('auth_provider', 'github');
 
-        return redirect()->route('register.success', $utmParameters);
+        return redirect()->route('register.success', $attributionParameters);
     }
 }
diff --git a/app/Http/Controllers/Auth/GoogleController.php b/app/Http/Controllers/Auth/GoogleController.php
index f7e1b5da..378ab9b9 100644
--- a/app/Http/Controllers/Auth/GoogleController.php
+++ b/app/Http/Controllers/Auth/GoogleController.php
@@ -5,7 +5,7 @@
 namespace App\Http\Controllers\Auth;
 
 use App\Actions\User\CreateUser;
-use App\Http\Controllers\Auth\Concerns\PreservesUtmParameters;
+use App\Http\Controllers\Auth\Concerns\PreservesAttributionParameters;
 use App\Http\Controllers\Controller;
 use App\Models\User;
 use Illuminate\Auth\Events\Registered;
@@ -16,11 +16,11 @@
 
 class GoogleController extends Controller
 {
-    use PreservesUtmParameters;
+    use PreservesAttributionParameters;
 
     public function redirect(Request $request): RedirectResponse
     {
-        $this->storeUtmParameters($request);
+        $this->storeAttributionParameters($request);
 
         return Socialite::driver('google-auth')->redirect();
     }
@@ -82,14 +82,14 @@ private function loginExistingUser(User $user, string $googleId): RedirectRespon
 
         Auth::login($user, remember: true);
 
-        $this->retrieveUtmParameters();
+        $this->retrieveAttributionParameters();
 
         return redirect()->route('app.home');
     }
 
     private function registerNewUser(\Laravel\Socialite\Contracts\User $googleUser): RedirectResponse
     {
-        $utmParameters = $this->retrieveUtmParameters();
+        $attributionParameters = $this->retrieveAttributionParameters();
 
         $user = CreateUser::execute([
             'name' => $googleUser->getName(),
@@ -97,7 +97,7 @@ private function registerNewUser(\Laravel\Socialite\Contracts\User $googleUser):
             'google_id' => $googleUser->getId(),
             'email_verified_at' => now(),
             'registration_ip' => request()->ip(),
-        ], $utmParameters);
+        ], $attributionParameters);
 
         event(new Registered($user));
 
@@ -105,6 +105,6 @@ private function registerNewUser(\Laravel\Socialite\Contracts\User $googleUser):
 
         session()->flash('auth_provider', 'google');
 
-        return redirect()->route('register.success', $utmParameters);
+        return redirect()->route('register.success', $attributionParameters);
     }
 }
diff --git a/app/Http/Controllers/Auth/RegisteredUserController.php b/app/Http/Controllers/Auth/RegisteredUserController.php
index 8b860a90..273f9f56 100644
--- a/app/Http/Controllers/Auth/RegisteredUserController.php
+++ b/app/Http/Controllers/Auth/RegisteredUserController.php
@@ -5,7 +5,7 @@
 namespace App\Http\Controllers\Auth;
 
 use App\Actions\User\CreateUser;
-use App\Http\Controllers\Auth\Concerns\PreservesUtmParameters;
+use App\Http\Controllers\Auth\Concerns\PreservesAttributionParameters;
 use App\Http\Controllers\Controller;
 use App\Http\Requests\App\Auth\RegisterRequest;
 use Illuminate\Auth\Events\Registered;
@@ -17,11 +17,11 @@
 
 class RegisteredUserController extends Controller
 {
-    use PreservesUtmParameters;
+    use PreservesAttributionParameters;
 
     public function create(Request $request): Response
     {
-        $this->storeUtmParameters($request);
+        $this->storeAttributionParameters($request);
 
         return Inertia::render('auth/Register', [
             'email' => $request->query('email'),
@@ -32,7 +32,7 @@ public function create(Request $request): Response
 
     public function store(RegisterRequest $request): RedirectResponse
     {
-        $utmParameters = $this->retrieveUtmParameters();
+        $attributionParameters = $this->retrieveAttributionParameters();
 
         $user = CreateUser::execute([
             'name' => $request->validated('name'),
@@ -40,7 +40,7 @@ public function store(RegisterRequest $request): RedirectResponse
             'password' => $request->validated('password'),
             'is_invite' => $request->isInviteRegistration(),
             'registration_ip' => $request->ip(),
-        ], $utmParameters);
+        ], $attributionParameters);
 
         event(new Registered($user));
 
@@ -56,6 +56,6 @@ public function store(RegisterRequest $request): RedirectResponse
 
         session()->flash('auth_provider', 'email');
 
-        return redirect()->route('register.success', $utmParameters);
+        return redirect()->route('register.success', $attributionParameters);
     }
 }
diff --git a/app/Jobs/PostHog/SyncUser.php b/app/Jobs/PostHog/SyncUser.php
index c1d355c3..64816807 100644
--- a/app/Jobs/PostHog/SyncUser.php
+++ b/app/Jobs/PostHog/SyncUser.php
@@ -6,6 +6,7 @@
 
 use App\Models\User;
 use App\Services\PostHogService;
+use App\Support\AttributionKeys;
 use Illuminate\Bus\Queueable;
 use Illuminate\Contracts\Queue\ShouldQueue;
 use Illuminate\Foundation\Bus\Dispatchable;
@@ -37,10 +38,18 @@ public function handle(PostHogService $postHog): void
             return;
         }
 
+        $attribution = collect(AttributionKeys::all())
+            ->mapWithKeys(fn (string $key) => [$key => $user->{$key}])
+            ->filter()
+            ->all();
+
         $postHog->identify($user->id, [
             '$email' => $user->email,
             '$name' => $user->name,
-            '$set_once' => ['signed_up_at' => $user->created_at?->toIso8601String()],
+            '$set_once' => [
+                'signed_up_at' => $user->created_at?->toIso8601String(),
+                ...$attribution,
+            ],
         ]);
 
         if ($user->account_id) {
diff --git a/app/Models/User.php b/app/Models/User.php
index dd9795db..95788b56 100644
--- a/app/Models/User.php
+++ b/app/Models/User.php
@@ -44,6 +44,12 @@ class User extends Authenticatable implements MustVerifyEmail, OAuthenticatable
         'utm_campaign',
         'utm_term',
         'utm_content',
+        'gclid',
+        'fbclid',
+        'li_fat_id',
+        'ttclid',
+        'rdt_cid',
+        'epik',
         'registration_ip',
         'persona',
         'goals',
diff --git a/app/Support/AttributionKeys.php b/app/Support/AttributionKeys.php
new file mode 100644
index 00000000..c7e2e854
--- /dev/null
+++ b/app/Support/AttributionKeys.php
@@ -0,0 +1,44 @@
+<?php
+
+declare(strict_types=1);
+
+namespace App\Support;
+
+/**
+ * UTM parameters and ad click IDs captured before signup (query string ->
+ * session -> persisted on the users row), shared by
+ * App\Http\Controllers\Auth\Concerns\PreservesAttributionParameters (capture)
+ * and App\Jobs\PostHog\SyncUser (forwarding to PostHog).
+ */
+final class AttributionKeys
+{
+    public const array UTM = [
+        'utm_source',
+        'utm_medium',
+        'utm_campaign',
+        'utm_term',
+        'utm_content',
+    ];
+
+    /**
+     * Per-platform ad click IDs (Google, Meta, LinkedIn, TikTok, Reddit,
+     * Pinterest). Adding a new ad network's click ID is just one more key
+     * here.
+     */
+    public const array CLICK_ID = [
+        'gclid',
+        'fbclid',
+        'li_fat_id',
+        'ttclid',
+        'rdt_cid',
+        'epik',
+    ];
+
+    /**
+     * @return list<string>
+     */
+    public static function all(): array
+    {
+        return [...self::UTM, ...self::CLICK_ID];
+    }
+}
diff --git a/database/migrations/2026_08_11_171700_add_click_id_columns_to_users_table.php b/database/migrations/2026_08_11_171700_add_click_id_columns_to_users_table.php
new file mode 100644
index 00000000..ff97aa22
--- /dev/null
+++ b/database/migrations/2026_08_11_171700_add_click_id_columns_to_users_table.php
@@ -0,0 +1,29 @@
+<?php
+
+declare(strict_types=1);
+
+use Illuminate\Database\Migrations\Migration;
+use Illuminate\Database\Schema\Blueprint;
+use Illuminate\Support\Facades\Schema;
+
+return new class extends Migration
+{
+    public function up(): void
+    {
+        Schema::table('users', function (Blueprint $table): void {
+            $table->text('gclid')->nullable()->after('utm_content');
+            $table->text('fbclid')->nullable()->after('gclid');
+            $table->text('li_fat_id')->nullable()->after('fbclid');
+            $table->text('ttclid')->nullable()->after('li_fat_id');
+            $table->text('rdt_cid')->nullable()->after('ttclid');
+            $table->text('epik')->nullable()->after('rdt_cid');
+        });
+    }
+
+    public function down(): void
+    {
+        Schema::table('users', function (Blueprint $table): void {
+            $table->dropColumn(['gclid', 'fbclid', 'li_fat_id', 'ttclid', 'rdt_cid', 'epik']);
+        });
+    }
+};
diff --git a/tests/Feature/Auth/SignupClickIdTrackingTest.php b/tests/Feature/Auth/SignupClickIdTrackingTest.php
new file mode 100644
index 00000000..e6fa5541
--- /dev/null
+++ b/tests/Feature/Auth/SignupClickIdTrackingTest.php
@@ -0,0 +1,215 @@
+<?php
+
+declare(strict_types=1);
+
+use App\Models\User;
+use Laravel\Socialite\Facades\Socialite;
+use Laravel\Socialite\Two\User as SocialiteUser;
+
+beforeEach(fn () => config()->set('trypost.self_hosted', false));
+
+test('email registration saves ad click ids from the register page query string', function () {
+    $clickIds = [
+        'gclid' => 'gclid-value',
+        'fbclid' => 'fbclid-value',
+        'li_fat_id' => 'li-fat-id-value',
+        'ttclid' => 'ttclid-value',
+        'rdt_cid' => 'rdt-cid-value',
+        'epik' => 'epik-value',
+    ];
+
+    $this->get(route('register', $clickIds));
+
+    $this->post(route('register.store'), [
+        'name' => 'Click User',
+        'email' => 'click@example.com',
+        'password' => 'Password123!',
+    ])
+        ->assertRedirect(route('register.success', $clickIds, absolute: false));
+
+    $this->assertDatabaseHas('users', [
+        'email' => 'click@example.com',
+        ...$clickIds,
+    ]);
+});
+
+test('email registration without click ids saves null columns', function () {
+    $this->post(route('register.store'), [
+        'name' => 'No Click User',
+        'email' => 'no-click@example.com',
+        'password' => 'Password123!',
+    ]);
+
+    $this->assertDatabaseHas('users', [
+        'email' => 'no-click@example.com',
+        'gclid' => null,
+        'fbclid' => null,
+        'li_fat_id' => null,
+        'ttclid' => null,
+        'rdt_cid' => null,
+        'epik' => null,
+    ]);
+});
+
+test('click id values longer than 255 characters are stored in full, unlike utm parameters', function () {
+    $longValue = str_repeat('a', 300);
+
+    $this->get(route('register', ['gclid' => $longValue]));
+
+    $this->post(route('register.store'), [
+        'name' => 'Long Click User',
+        'email' => 'long-click@example.com',
+        'password' => 'Password123!',
+    ]);
+
+    $user = User::where('email', 'long-click@example.com')->first();
+
+    expect($user->gclid)->toBe($longValue);
+});
+
+test('google registration saves ad click ids captured before the oauth round-trip', function () {
+    $clickIds = ['gclid' => 'g-click', 'fbclid' => 'fb-click'];
+
+    $this->get(route('auth.google.redirect', $clickIds));
+
+    $socialiteUser = new SocialiteUser;
+    $socialiteUser->id = 'g-click-user';
+    $socialiteUser->name = 'Google Click';
+    $socialiteUser->email = 'google-click@example.com';
+
+    Socialite::shouldReceive('driver')
+        ->with('google-auth')
+        ->andReturn($driver = Mockery::mock());
+
+    $driver->shouldReceive('user')
+        ->andReturn($socialiteUser);
+
+    $this->get(route('auth.google.callback'))
+        ->assertRedirect(route('register.success', $clickIds, absolute: false));
+
+    $this->assertDatabaseHas('users', [
+        'email' => 'google-click@example.com',
+        ...$clickIds,
+    ]);
+});
+
+test('github registration saves ad click ids captured before the oauth round-trip', function () {
+    $clickIds = ['li_fat_id' => 'li-click', 'ttclid' => 'tt-click'];
+
+    $this->get(route('auth.github.redirect', $clickIds));
+
+    $socialiteUser = new SocialiteUser;
+    $socialiteUser->id = 'gh-click-user';
+    $socialiteUser->name = 'GitHub Click';
+    $socialiteUser->email = 'github-click@example.com';
+
+    Socialite::shouldReceive('driver')
+        ->with('github')
+        ->andReturn($driver = Mockery::mock());
+
+    $driver->shouldReceive('scopes')
+        ->andReturnSelf();
+
+    $driver->shouldReceive('user')
+        ->andReturn($socialiteUser);
+
+    $this->get(route('auth.github.callback'))
+        ->assertRedirect(route('register.success', $clickIds, absolute: false));
+
+    $this->assertDatabaseHas('users', [
+        'email' => 'github-click@example.com',
+        ...$clickIds,
+    ]);
+});
+
+test('existing google user login consumes the click id session so it does not leak to a later signup', function () {
+    User::factory()->create([
+        'email' => 'existing-click@example.com',
+        'google_id' => 'g-existing-click',
+    ]);
+
+    $this->get(route('auth.google.redirect', ['gclid' => 'stale-click']));
+
+    $socialiteUser = new SocialiteUser;
+    $socialiteUser->id = 'g-existing-click';
+    $socialiteUser->name = 'Existing Click User';
+    $socialiteUser->email = 'existing-click@example.com';
+
+    Socialite::shouldReceive('driver')
+        ->with('google-auth')
+        ->andReturn($driver = Mockery::mock());
+
+    $driver->shouldReceive('user')
+        ->andReturn($socialiteUser);
+
+    $this->get(route('auth.google.callback'))
+        ->assertRedirect(route('app.home'));
+
+    expect(session()->get('attribution_parameters'))->toBeNull();
+});
+
+test('existing github user login consumes the click id session so it does not leak to a later signup', function () {
+    User::factory()->create([
+        'email' => 'existing-gh-click@example.com',
+        'github_id' => 'gh-existing-click',
+    ]);
+
+    $this->get(route('auth.github.redirect', ['gclid' => 'stale-gh-click']));
+
+    $socialiteUser = new SocialiteUser;
+    $socialiteUser->id = 'gh-existing-click';
+    $socialiteUser->name = 'Existing GitHub Click User';
+    $socialiteUser->email = 'existing-gh-click@example.com';
+
+    Socialite::shouldReceive('driver')
+        ->with('github')
+        ->andReturn($driver = Mockery::mock());
+
+    $driver->shouldReceive('scopes')
+        ->andReturnSelf();
+
+    $driver->shouldReceive('user')
+        ->andReturn($socialiteUser);
+
+    $this->get(route('auth.github.callback'))
+        ->assertRedirect(route('app.home'));
+
+    expect(session()->get('attribution_parameters'))->toBeNull();
+});
+
+test('an empty query string value is treated the same as an absent one, not stored as an empty string', function () {
+    // Some ad/email templates always append every tracking key, leaving
+    // unfilled slots blank (?utm_source=&gclid=) instead of omitting them.
+    $this->get(route('register', ['utm_source' => '', 'gclid' => '']));
+
+    $this->post(route('register.store'), [
+        'name' => 'Empty Param User',
+        'email' => 'empty-param@example.com',
+        'password' => 'Password123!',
+    ]);
+
+    $this->assertDatabaseHas('users', [
+        'email' => 'empty-param@example.com',
+        'utm_source' => null,
+        'gclid' => null,
+    ]);
+});
+
+test('click ids and utm parameters are both saved when present together', function () {
+    $this->get(route('register', [
+        'utm_source' => 'google',
+        'gclid' => 'mixed-click',
+    ]));
+
+    $this->post(route('register.store'), [
+        'name' => 'Mixed User',
+        'email' => 'mixed@example.com',
+        'password' => 'Password123!',
+    ]);
+
+    $this->assertDatabaseHas('users', [
+        'email' => 'mixed@example.com',
+        'utm_source' => 'google',
+        'gclid' => 'mixed-click',
+    ]);
+});
diff --git a/tests/Feature/Auth/SignupUtmTrackingTest.php b/tests/Feature/Auth/SignupUtmTrackingTest.php
index 9a80e10e..075099af 100644
--- a/tests/Feature/Auth/SignupUtmTrackingTest.php
+++ b/tests/Feature/Auth/SignupUtmTrackingTest.php
@@ -146,7 +146,7 @@
     $this->get(route('auth.google.callback'))
         ->assertRedirect(route('app.home'));
 
-    expect(session()->get('utm_parameters'))->toBeNull();
+    expect(session()->get('attribution_parameters'))->toBeNull();
 });
 
 test('invitation registration does not include utm parameters in its redirect', function () {
@@ -317,5 +317,5 @@
     $this->get(route('auth.github.callback'))
         ->assertRedirect(route('app.home'));
 
-    expect(session()->get('utm_parameters'))->toBeNull();
+    expect(session()->get('attribution_parameters'))->toBeNull();
 });
diff --git a/tests/Feature/Jobs/PostHog/SyncUserTest.php b/tests/Feature/Jobs/PostHog/SyncUserTest.php
index 9e5dc252..075ea845 100644
--- a/tests/Feature/Jobs/PostHog/SyncUserTest.php
+++ b/tests/Feature/Jobs/PostHog/SyncUserTest.php
@@ -54,6 +54,53 @@
     });
 });
 
+test('handle forwards ad click ids as first-touch person properties when present', function () {
+    $this->user->update(['gclid' => 'g-123', 'fbclid' => 'fb-456']);
+    Queue::fake();
+
+    (new SyncUser((string) $this->user->id))->handle(app(PostHogService::class));
+
+    Queue::assertPushed(SendEvent::class, function ($job) {
+        return $job->payload['properties']['$set_once']['gclid'] === 'g-123'
+            && $job->payload['properties']['$set_once']['fbclid'] === 'fb-456';
+    });
+});
+
+test('handle forwards utm parameters as first-touch person properties when present', function () {
+    $this->user->update(['utm_source' => 'google', 'utm_medium' => 'cpc', 'utm_campaign' => 'spring-launch']);
+    Queue::fake();
+
+    (new SyncUser((string) $this->user->id))->handle(app(PostHogService::class));
+
+    Queue::assertPushed(SendEvent::class, function ($job) {
+        return $job->payload['properties']['$set_once']['utm_source'] === 'google'
+            && $job->payload['properties']['$set_once']['utm_medium'] === 'cpc'
+            && $job->payload['properties']['$set_once']['utm_campaign'] === 'spring-launch';
+    });
+});
+
+test('handle omits attribution properties when none are set', function () {
+    Queue::fake();
+
+    (new SyncUser((string) $this->user->id))->handle(app(PostHogService::class));
+
+    Queue::assertPushed(SendEvent::class, function ($job) {
+        $setOnce = $job->payload['properties']['$set_once'];
+
+        return ! array_key_exists('utm_source', $setOnce)
+            && ! array_key_exists('utm_medium', $setOnce)
+            && ! array_key_exists('utm_campaign', $setOnce)
+            && ! array_key_exists('utm_term', $setOnce)
+            && ! array_key_exists('utm_content', $setOnce)
+            && ! array_key_exists('gclid', $setOnce)
+            && ! array_key_exists('fbclid', $setOnce)
+            && ! array_key_exists('li_fat_id', $setOnce)
+            && ! array_key_exists('ttclid', $setOnce)
+            && ! array_key_exists('rdt_cid', $setOnce)
+            && ! array_key_exists('epik', $setOnce);
+    });
+});
+
 test('handle dispatches SyncAccountUsage with the user account id', function () {
     Queue::fake();