If it's auction format you can take a look at their feedback and see if they keep buying the same item and the feedback they have left to previous sellers. I've stopped about 5 of them so far, but you have to be vigilant at the end of your auctions and keep look out.
Most likely your competitors will not have the time to snipe the end of the auction they will put up really high automatic bids and you can just cancel them. For buy it now, not much you can do but stop it from happening again from the same competitor, unless someone knows a way...
Posted from Vegas waiting for a poker table at the Bellagio, wish me luck!!!
__________________ “You have to learn the rules of the game. And then you have to play better than anyone else.”
-Albert Einstein |