Depends on the bounty project you have participated just make sure its not a scam.I have joined a bounty that last for 6 months and only few participants joined and it took 1 month for them to distribute the token and another 1 month for the exchange but its definitely worth it.Though there are others that's not worth it because they did not gave the exact allocation of tokens that stated on the bounty thread and some due to lots of participants only few tokens you can accumulate.