Well through doing a bounty campaign like say translating a whitepaper you really get to know the project in and out, the team and everything about it. I see it as a great source of information while you earn a reward for learning about something you might not have otherwise. Airdrops, there are a lot of scams. Im definitely with bounty campaigns, but nothing wrong if you see something in the ico doing an airdrop and wish to sign up for it and get some free coins.