I want to ask how does the people that do bounty make money.I mean they are giving away money for free.How is it profitable for ICO teams?
Because very less amount of people invest in their ICO through bounty.

They are not giving any free money,you are doing the job as advertising their project so you are doing some job to get that money.
Actually they are making lot of money than you think,the advertisement of the project is very important if they want to get more investors so they will allocate some funds from the token or coin creations so they are using that money for the advertisement,it is the investors money not their own.
Some ICOs will reach their caps value in some minutes after it was launched so it needs to be a good project too to get succeed if there is less investors then the project may not worth to invest.
Yes we are doing job to get that money and our work is very imposrtant for the success of ICOs so rewarding us with the little bit earning from them is affordable for them.But what we need to do is find the right project it is more worth than doing signature campaigns but you need time to cashout the tokens.