There are so many bounties that offers signature campaign it is good for you to find the best signature campaign. Makes some research on how to choose good bounties you can also look for this https://bitcointalk.org/index.php?board=238.0. Try to find best bounty manager before choosing campaign because sometimes it depends on the bounty manager wherein you can determine if a particular bounty is good or not and always don't forget to avoid being scam use your clever minds and instincts.