> Buying with Prime is a pain in the ass, since half the stuff they sell isn't eligible.
From what I can see, Amazon sells very little that isn't Prime eligible. There are lots of "Marketplace" offerings that aren't Prime eligible, but you can filter those out by clicking the "Prime" checkbox that pops up on the left whenever you're in a search or category view.
From the user's (i.e. my) perspective, "Marketplace" offerings are still things that Amazon sells. The "Prime" checkbox doesn't work well. It doesn't filter out add-on items (which can be removed with another checkbox), and it doesn't do a very good job of only showing me Prime items. Searching for hard drives, just as a random example, I get results where the primary seller isn't Prime, and the Prime option is either more expensive than what's listed, or is a used or refurbished item. I'm sure there's a combination of checkboxes that will do what I want, but they sure don't seem to be optimizing for the common case.
From what I can see, Amazon sells very little that isn't Prime eligible. There are lots of "Marketplace" offerings that aren't Prime eligible, but you can filter those out by clicking the "Prime" checkbox that pops up on the left whenever you're in a search or category view.