It does give a return on a daily basis, but unless you are holding a large amount, you're not going to make money worth shouting about. I hold a very small amount of Kucoin, single digits, and have bought them all with free BTC given to me by sharing their promotional posts on Twitter. Never going to make me a fortune, but it's free, so why not. Either way, I like Kucoin, it's an exchange that is growing in popularity, and I can see the value increasing over the next couple of years. Might as well grab some 'dividends' along the way.