Let's say if they sent 1m token to 50k addresses then maybe almost 50k peoples will know about the project and those 50k peoples will probably look for the price and will also try to learn more about that project.
Maybe some peoples will convert and will do promotional works (bounty) for them to earn more of those tokens. And from promotion, they may get investors to get funded up their project.
They send such low amount because they don't want peoples to dump the tokens when they will list the token in exchange. It's just a marketing startegy imo, and win win thing for them.