I only ever look at prime a couple of times a year and it just keeps getting worse. You used to be able to filter out the shows they demand you pay them even more to see. That option seems to have vanished a while ago, but I found I could still search using terms like "free movies" or "included with prime" and get a list of shows my membership fee had already paid for. A couple weeks ago I tried searching and the results were still full of shows where they wanted more money. Pretty sure I heard somewhere they were going to be adding ads to the shows themselves too.
Between amazon's increasingly limited and ad filled video service, their inability to deliver packages when they say they will, the total lack of quality control in what they sell/ship, and the fact that I'm finding more items that don't even have "free" shipping with prime, I'm about ready to cancel.