A lot of ads on ebay are popping up where they 'only accept bitcoins as payment'. What do you guys think of this?
Scam, scammity, scam, scam.
They want Bitcoin because transactions are non-reversible. One of the weaknesses of Bitcoin is the lack of arbitration for this sort of thing. (Since arbitration requires centralized control, it's an unavoidable weakness in the design. It's also a strength, depending on your POV/needs/circumstances. Certainly, these scammers count that as a strength.) I'd use a well-known 3rd party escrow service for this sort of transaction if I didn't already know the person.
Because of the lack of consumer protection, Bitcoin only works well for in-person transactions or trusted merchants.