Bounties are great ways of getting rewarded by companies for promoting their ICO on your social media channels like Telegram,Twitter, Facebook,You tube, Linkedin, Medium,Reddit etc. You are supposed to either like the posts or videos or make your own posting on the your social media groups .   Bounties are also offered for Signature campaign but for that you need to have  advanced to certain level in Bitcoin Talk .

Basis  your work done you are given the coins after the ICO .  But to earn bounties following should be kept under consideration
1)age of your social media accounts older your accounts  you would earn more
2) No of followers should be genuine   (greater no of followers more bounty )
But  would advise if you could start with joining companies offering 1)  AIRDROPS   as they are much easy to earn  and then gradually move to bounty