I have been doing bounties for some time and I have encountered some bounty effort that are not paid for.  

1. Hashcard - scam exit
2. Blackfolio - did not reach softcap
3. BCharity - did not reach softcap
4. Safein - project is cancelled
5. Impressio - scam exit
6. Root blockchain - didn't get enough private investors

I learned a lesson here.  I have to be more selective in the future in choosing bounties, as much as choosing an ICO to invest.  

Do you have any similar experience?  Please share so that others may learn.