Yep. Here's the ad sales page which goes through all the various options, including showing ads on the pause screen and including ads when you delete a show and in the menu that lists your episodes of a show. It's gross.
http://www.tivo.com/tivoadvertising/
(Your ad blocker may stop that page from working properly.)
There was also the thumb integration (you could thumbs-up some ads from either live tv or your recordings, which would pull up a new page with info about whatever was being advertised, occasionally a video), but this is about as unintrusive as it gets (a small icon on the top right whenever a compatible ad is played).
Has this changed in the newer revs? I'm honestly curious.