Derogatory term used in online gaming (see MMORPG, MMOG) to describe someone who has not earned the equipment or character they are using. Often high-level players will use eBay to sell premium equipment they have earned in-game, or sometimes sell an entire account, with all characters and equipment, exchanging real-world money for in-game items. This practice is generally discouraged by the companies that produce and host the games. Someone who has acquired their character or gear in this way is generally recognizable by inept game-play, which would not be expected of someone who has actually earned their position.
Player 1: I just met this guy, a level 195 Enforcer wearing a full suit of living dragonscale armor, and he didn't even know how to find the shops in OldAthen.
A: Did you know that she sold her grandmother's ashtray on eBay for a ton of cash?
C: Gosh, maybe I shoudl try it
A: Yeah, she is such an ebayer, she bought all her clothes there
B: <pant> Hey! Look what I just found....!
In Massively Multiplayer Online Gaming an "Ebayer" is someone who's gone and bought a high level character off of Ebay. Typically they don't have a clue what they're doing as the ones who do know, don't get found out.
Doctor: We're so sorry, Mr and Mrs Smith, but your child was born with Trisomy 21.
Mr and Mrs Smith: You mean...you mean...
Doctor: Yes, I'm affraid that your child is an ebayer... Im so sorry. Down the road, you will probably want to consider institutionalization.
Look at that guy pissing on himself... WHAT AN EBAYER!
I gave that ebayer a 10 dollar bill and they gave me change for a fifty... who says ebayers are useless?