Most of the SCAMs out there have real token. You can receive their token for your work (join airdrop, bounty, transfer ETH).
But, in the end, most of those tokens will be worthless, it means you exchanged your ETH for zero-value-token.
IMO, I will never buy or send my ETH to any project in which they are trying to imitate famous coin, such as, NEO Cash, ETH blue, ETH key, etc.
If you want to join their airdrop, just do it, as long as it doesn't take your time too much, it's fine.