Actually, a lot of ads (on Facebook at least) have the &quot;I already have this&quot; option.<p>The type of Facebook ads that are heavily leveraged by Amazon are called &quot;re-targeting ads&quot;. True to their name, they target you again for something you&#x27;ve already looked at. Usually, they serve to remind person being served the ad about a product they looked at previously and <i>didn&#x27;t</i> purchase. They&#x27;re actually very effective (which is why Amazon and others continue to use them, despite how &quot;creepy&quot; they feel). The fact that you&#x27;re shown re-targeted ads after already purchasing an item points to a bug in Amazon&#x27;s system and how it interacts with Facebook.