A lot of people have their own description of bounty. Some say its an easy way of earning tokens without investing. To me, bounty is also a form of investment but in this case, we invest with our time and energy either than physical cash
Firstly, a bounty or bounty campaign is an offer made by many startups, websites, and software developers which enables individuals to receive recognition and compensation for performing marketing tasks, reporting bugs or improving a product/service. ICO startups and the token economy in general are excellent environment for bounty campaigns.
Now, if you participate in bounties, you receive reward in coin /token, and this could be "hold" as an investment for certain period of time. For example if you participate in signature bounty (Facebook, Twitter telegram, content, etc), the rewards received could be regarded as an investment just thesame way as investors purchased during ICOs.