First, I'll admit that I haven't bought or sold anything on EBay. Not that I haven't tried, though.
First, I tried to sell stuff. EBay does not allow you to sell anything unless you give them your bank account number. That means you either open a separate bank account just for EBay transactions, or you're taking a big chance with your main bank account number floating out there in cyberspace. I declined.
They told me that that policy is to keep fraudulent sellers away. But instead, it kept me - an honest would-be seller - away, and lets in sellers like those described below.
Then I tried to buy stuff. I looked in the section for LCD computer monitors, and what did I find? A dozen or so ads for LCD computer monitors amid more than a hundred spam ads for get-rich-quick schemes and the like.
The worst ones advertised a large LCD monitor for less than $10, or even for free. Sounds too good to be true, and of course it is. What they're selling instead is a scheme for you to pretend to be a wholesaler, write a letter to the manufacturer, and attempt to get a free sample. Good grief! What kind of idiot could fall for a scheme like that? And why in the world does EBay allow such trash in their listings??
Most frustrating of all was that the sellers of this phony "merchandise" had very positive ratings! I looked at some of their reviews and the vast majority were obvious forgeries. So not only does EBay allow tons of spam in the auction listings, they apparently don't do much to police their ratings system either.
And after all that, just about everything you buy must be paid for with PayPal or money order rather than credit card, meaning that you have practically no recourse if you get cheated.
Altogether, EBay looks like a great way to get ripped off. If I order something from a recognized online merchant and pay with a credit card, it might cost a bit more, but at least I'll have some protection against fraud.