Airdrops are a good way to raise awerness of some ICO peoject, this is manily why it is done. Depends on an airdrop but usually I think it's around 30day before their ICO finishes, you have to read the rules - when they send it out you should receive your tokens the same day. Don't give out your personal information as easily just to sign up to some airdrop. Create an email just for airdrops etc. because this info could easily be sold to some other spammers, sepcially if an ICO is a scam one and you filled form with your information in hopes to get some free coins.
Most people fnd themselfs dumping their coins/tokens the first time they get on exchanges and you could look like 5-30$ profit this way (price can vary a lot, this is just as an example). Although if you really believe in some token you could hold it for few months and see if it price increases or if it will drop in future. There are some tokens from last year that managed to do like 10x the price of an ICO so even if you got like 5$ from an airdrop you could get like 50$ or more in returns depends when you sell.
It all depends on an airdrop how much in value you will get out of it. But consider that this is really risky, all of these ICOs airdrops are relativly easy to pick up but maybe not all of them will pay at end, you will often forget where have you applied if you don't keep track.
All in all if you are willing to earn crypto currency, I'd suggest you to learn some skill and offer your service because airdrops at the end of the day is like "zombie" work because there is not any benefit for you when you look at it it is just dull thing to do: click this and that, fill form etc. I don't say airdrops can't give you nice profit, but for the long run you will could earn more by having particular skills.
Thank you very much!
Your answer and advice seem to be the most useful for me as a newbie.
And thanks the author for this thread!