Up to you, unlikely any airdrops are going to make you a fortune, but you can make a bit here and there. Most will be worth less than a few dollars, so transferal and withdrawal fees will eat up any 'profit'. I tend to avoid most airdrops now and only do ones where I'm impressed with the project, that way if I have to hold them, I'm happy to trade and increase my portfolio. Each to their own though, if you want to sell them as soon as you get them, then go for it.