What Instagram and TikTok know about you to show you ads

October 27, 2026 · 6 min read

You talk about a product and an ad shows up the next day? In the vast majority of cases, no microphone is involved. Social networks have far more effective sources, and they are listed in black and white in your data export.

1. The interests assigned to you

Based on the videos you watch, the accounts you follow and the posts you like, the platform puts you in categories: “Travel”, “Fitness”, “Cooking”… Advertisers then use these categories to choose who sees their ads. Some are surprisingly accurate, others completely wrong.

2. Customer lists uploaded by brands

This is the most surprising category. A brand where you have an account, or that got your contact details some other way, can upload a list of email addresses or phone numbers to the ad platform. If yours is on it, the brand can target you directly.

In the Instagram export, these advertisers are listed in the file of advertisers using your activity or information, marked as using a customer list. Many people discover companies they have never been customers of.

3. Your activity outside the app

Many websites and apps include tracking tools provided by Meta or TikTok. When you view a product, add an item to your cart or make a purchase, the information can be sent to the platform, which links it to your account.

On TikTok, the export has a dedicated section for off-TikTok activity, with the name of each website or app and the type of action (page view, add to cart, purchase…).

See your own data in seconds

Reading these files by hand is tedious. FollowersChecker’s Ads tab brings them together on one page:

• the interests and categories assigned to you;
• the brands that have your email or phone number, and those that follow your activity;
• the websites and apps that send your activity to TikTok;
• the brands whose ads you see the most.

How to limit targeting

1. Clean up your interests in the app’s ad preferences (Accounts Center → Ad preferences on Instagram, Settings → Ads on TikTok).
2. Turn off the use of your activity on partner websites, an option both platforms offer.
3. Refuse advertising cookies on the websites you visit, and limit ad tracking in your phone’s settings.
4. Use your privacy rights with brands: you can ask where your data comes from and demand that it be deleted. FollowersChecker generates a ready-to-send letter for each brand.

Your rights in short

In Europe, the GDPR gives you the right to access your data (article 15), to have it erased (article 17) and to object to its use for marketing (article 21). The company must answer within one month. Without an answer, you can complain to your country’s data protection authority. Similar rights exist in many other places, such as California (CCPA).