If I have a few mins to kill during the day (usually when waiting for ETH/BTC to hit the exchanges from my wallet) Ill sign up for an airdrop or two. Most of the ones that I have either haven't hit exchanges or are worth under $1.
TRON (TRX) was the first one for me that actually did something.
500 free TRX peaked at ~$30 and is currently worth ~$19
HODLing!
I do not really like the airdrop, because I feel wasted my time, and most airdrops today are scams. I'd rather do something more definite and I'd rather have a signature campaign.
Well how hard is it to sign up for free tokens? I have have an email acct and eth wallet separately with the sole purpose for airdrop signups. Wouldn't hurt to be safe. People are getting good money from it as well. Better than bounties.