Compare bounty campaign and airdrop just can't. This is completely different levels of work and income. In airdrop You need to fill in a few fields and all. In the bounty of the campaign all different. You should read the WhitePaper to understand the essence of the project. Then choose a direction and be accountable every week. You will spend a lot of time but the rewards will be great.
Airdrop is very simple but usually its coin from airdrop result can be valuable and some are not valuable. Different with the gift, The gift is generated from hard work and definitely according to the future that we can.
Some airdrops might be worth more then bounty, since the coins aren't created equal.
For the same coin, bounty should generate more but might still be worth less then another coins airdrop.
You should do your research and read whitepaper etc