you can check it on the bounty section, there are many good signature campaign there. There are many signature campaigns that is good but im limited to join in some signature campaign so it is good if you research and find a good one.
today there is quite a lot of bounty companies that require services in the distribution of the company's signature. But not for all users, the conditions may be pleasant, as some Bounty manager and reduces the percentage of the total pool or exhibited a very uncomfortable condition.