IMHO you can participate airdrop if you have a lot of free time. It like free gambling) Some can give you profit, but you will have to participate hundreds of them)
Airdrops are actually always the easiest thing to participate in and just some one-time thing, but in most cases, I always see them as waste of that time, no matter how little the time is anyway. Most of the time, I have never really seen anyone come out to say they participated in an airdrop that they are sure will give them something substantial in the long run.
However, airdrops because of the little value the participant gets makes them an easy hold for the long term anyway as long as you participated in coins or tokens with long term usage and potentials.