I'd be interested in this too.
There's no point in starting promotions unless it brings in new buyers. I have been tempted to place bids on some items but I won't because I know I'd win them at a loss to the seller and I don't want to do that.
From experience there are some traders who relish "sales drives" like this, buy all the stock and then sell it on elsewhere for a fat profit.
Personally I'm happier knowing I'm selling a good choice of items at a competitive price.
I'm sorry but this just seems like a bit of a gimmick that's going to get you nowhere fast