I'm going to buy a bag of weed for you but I need the money up front. You'll see me again in 3, 4 or 5 days. Maybe a little longer.
When I get back to you, I don't have the weed but I do have your money. I used your pledge, and the pledges of others, so that I could buy a pound of weed and distribute it amongst my friends. If we keep doing this deal, sometimes you might get some weed.
Gee. So if you were a Mexican weed cartel and you wanted to destroy the domestic (US) weed suppliers, you'd always give people money for their weed, but seldom give them weed for their money. And then, once you had lots and lots of weed, you could sell it really, really cheap to the mid-level dealers and consumers who had always bought domestic weed... I bet that'd hurt the domestic people pretty badly, wouldn't it?
Sometimes I think that HRU* MPOE-PR occasionally makes a very good point:
Your story needs more Wall Street in it.
*His Royal Unpleasantness