Faucet amount is already indeed a sure money but as expected its just lesser unlike on airdrop tokens value isn't still there but might give you the chance on getting some decent amount but would depend on the project.
Both of these things will not give much money to the people spend time on it but it is a free thing so got a lot of popularity. Faucet money value one can check instantly but for the airdrop, coins need to wait until project get listed into exchanges. Once people know how to maximise their earnings online will slowly give up both of them. But few times every week I claim money on freebitco to get some free tickets to try my luck.
Nope, actually it does not worth to keep this all the time. Time that you spend and the result that you get from faucet is can't be compared because it is too little. You can count by yourselves, how much time do you need to get 0.01 btc? Are you sure you have this time just to harvest from.their faucet? Waiting airdrop will be just the same too, it only happens for some period of time so the effect will be just the same as faucet