The question is wrong. It is not what sells.. Actually not what but HOW..It is the way you sell and the thing you sell..
I'd venture to say 75% of the people online are high on something, so if you get high then buy a bunch of crap that seems interesting to you while you're high, you should be able to sell it at a profit when you're sober.
Just look for what's selling at the various online marketplaces. You're not going to get a detailed list here.
well, you can analyze what professional ebay sellers offer on ebay, but if you really want to make big $$ on ebay, you have to be first with a new product. Try to think ahead of what might be very profitable this season, try to sell a few items first and then go with wholesale.