Airdrops can be quite profitable when we have the fortune to join the right option, but it is difficult to find a good opportunity in the middle of the immense amount of airdrops that appear available every day. I think the most successful airdrops I've seen so far is Deeponion, although many seem to agree that this was not a true airdrop, but a signature campaign. Anyway, I think it is always advisable to be cautious when sharing our data or private information when registering in an airdrop.
A true airdrop or not does not matter.
You have always to do something for the free tokens.
Nothing is realy free nowadays.You just do not pay with money but with your time or your "ad space" etc...
When you get free WSPU2 from what I call an airdrop you have to come on my site and register.(register is to see you are there)
No one has the monopole of airdrops...each token rewarder can do like he want.