I have to bring up the morality thing of it/thrift supply, just because I've been thinking about it, and I think some of the arguments posted here are without merit.
You will NOT find a thrift that doesn't have any decent clothes because of re-sellers getting them. Most clothes are NOT resellable! Perfectly good clothes, even some NWT, will not bring in any profit on ebay. If your thrift store doesn't have a good selection, I guarantee it's not ebayer's fault
The list of re-sellable clothes is MUCH smaller than the amount of brands out there. For example, Gap, Old Navy, TCP, most gymboree, Circo, Cherokee, Samara, Healthtex, George, Buster Brown, Osh Kosh, KRU, Starter, Puma, need I go on? All these brands make completely adorable clothes, they are also not worth squat on ebay... unless maybe you did a big lot, but still you're only making around $2 a piece. So, is this making sense? There's no reason for ebayers to snatch up these very common brands, if your not finding anything wearable at your local thrift and you are in the market for these more common brands, then your thrift is not getting any of these brands in the first place. There are thrift stores that just have junk, and it has nothing to do with ebay... it has to do with who they are collecting from.
Okay, done with my rant... it just bothers me that people would think their crappy thrift store selection is due to resellers!