I have observed that there are lot as lot of selfdrop tokens nowadays. Others are requiring little fees, pay for the gas, while there's also some that you can directly add to your wallet. I mean can these tokens possibly make you rich?

because some are given millions of millions of tokens and if its price goes at least $1 then congratulate yourself (if you have joined this campaign) for being an instant millionaire. But my question is why are these "ALMOST FREE TOKENS" arising all of a sudden? What could the developer benefit if they give their tokens in exchange of a little gas you pay?