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!
My first Airdrop was penis coin it it was never listed.
the rest, i get nothing in the end
The very name of the coin did not foreshadow the benefits. In the meantime, airdrops of more promising projects (but also rare ones) could bring me several hundred bucks, while spending 5 minutes to register.