Just some couple rule for airdrop section category
You know or you should know many new coin airdrop some of them (% can vary on the project ) and so coin/tokens are given for free.
You will be required to join / follow on telegram / twitter / facebook ( maybe some other site too) and will be asked to like /retweet / repost or spread your link or project link.
Almost all airdrop require also a Bitcointalk account and ethereum address of which you own private key it could be myetherwallet or metamask extension .for chrome.. but surely other wallet can be used. “be aware most eth airdrop require wallet address not empty at least 0.01ETH” some airdrop can require alternative coin wallet ( i saw btc and nem on new airdrop)
So rule of AIRDROP can vary and change be prepared. Bounty can be added too but we must follow the rule given to us from official site.