Airdrops were so popular among the crypto-community over the years. One of the key features of the airdrops is, it gives every participant a chance to get some free tokens by completing few tasks. Most importantly it is totally free of charge. But nowadays we frequently see a trend where the organizers of some of the airdrops ask to send a small fee prior to sending the tokens. In some cases, they put a condition saying that in order to withdraw tokens or any fund received from the sale of tokens, it is mandatory to take part in their ICOs. I would rather call such events as "Scam-drops" as they not only dilute the meaning of airdrops, but also make people to move away from future events due to lack of trust.
Airdrop programs that require participants to pay a small fee are projects that do not have the trust of investors. It is certainly a scam. Even though their token has entered the exchange, their token value will not increase. If you pay a $ 1-2 fee for token delivery, then the token value is only $ 0.1. this is public duping. we better not need to join an airdrop program like that.