I'm new to bitcointalk, thank you guys for help me understanding more about bounty campaign.
Bounty is best way to get some token and even more than airdrop since bounty do lot of tasks and need long time to follow the bounty program.
If project is a great one, lot of bounty participants joining that bounty, you may join all the campaign to maximize the chance to get maximum token/coin.
Airdrops and campaigns are considered as bounties . In twitter and Facebook you can join many campaigns as long as you want but unlike in signature campaign it is a one at a time work. You can choose only one bounty in signature campaign.