Ok I see. I think users are expecting to:
1. Click the link in the email
2. Arrive at a page that tells them that ad has been extended
3. OR arrive at a page that offers to extend their ad and a submit button
So, just arriving at their ad feels like something is missing -- plus with no way to see when the ad expires they have no way to confirm that anything has happened.
It sure would be nice if after all this time PP Classifieds cleaned this process up and put the expiration date on regular classified ads.