My feeling is most people would only open an ebay account if they saw something they were interested in and wanted to buy something or put in a bid for it .

That's the only reason I sign up to a lot of other websites (not auction websites, just company websites).

Ebay is advertising a fair bit on TV so it may be getting some new people browsing and signing up. So, it could be perfectly legit. Everyone has to start somewhere.

Having said that, some sales items admittedly are more high risk than others so if you feel uncomfortable about any aspect of a bid, better to cancel or block before the sale. There will be other buyers out there that you can sell to.