Airdrops and bounties is different from each other but there are also the token that we receive. Most shitcoins are from airdrops, they are only using it for donations.
I'd rather choose to participate in bounty campaigns that runs ICO, then afterwards you will receive the coin depends on your stake. You can sell it to BTC or fiat currency on exchanges where it has been listed or trade with other coins. You can also hold like what I have done and continue setting a price target to my other coins when I want to sell it, I made $5,000+ from Humaniq, I have 5292 HMQ sold to BTC bittrex at $1+