I've seen quite a few different bounties that are for the person that gets a token listed on an exchange. How does someone get a token listed on an exchange and a better question is how do they prove that they were the ones that got it listed?
It depends on what exchange developers want their token to be listed, because exchanges have different requirements and process listing new digital tokens and cryptocurrencies. If your token isn not used by huge community then the exchange will not going to make any money from listing it. Getting listed on big exchanges like Bittrex is not that easy, you should have a good team, with a support of big community and great project to make it easily to be listed on big exchanges, they will will only list a coin or token where they can make more money.
This link may help answer your questions:
https://www.coinist.io/how-to-get-your-digital-token-listed-on-an-exchange/