In my Tumblr page I have ads on the top and the bottom and even when I change the theme they don’t disappear. Can I remove the ads from the top and bottom of my Tumblr page?
Banner ads aren't a feature of Tumblr as yet. One possible culprit is the "IWantThis!" browser extension according to this article, which injects ads onto pages you visit.
The easiest way to check is probably to run through the uninstall instructions for your browser provided at the end of the FAQ here.
I had the same problem... I read below the little banner and it said it was powered by Coupou Idk what... If you go to the Chrome or Firefox or whatever you're using properties and check the extension, you'll probably find the extension that's causing it... Just remove it and you're done! :D
Hope it helps!