I don't participate in airdrops except for major bitcoin airdrops (forks) like bitcoin cash and bitcoin gold. Most airdrops require participants to provide their personal information and I don't feel comfortable giving my info away for a few altcoins.
I'm not also comfortable putting my info on suh spreadsheet. I tried to sign up before with one airdrop, I wasnt really interested with it but just giving a try.
You know what happened next? I have received another email from another ICO that is inviting me for their airdrop so I stopped.