That was a good analysis you did over there. Remember that there are so many ways of killing a cat, as the popular saying goes. Advertising is done in so many ways and signature campaigns are one huge ways of getting the big men to join. Have you ever thought of why majority of bounty stakes are mostly given to signature campaign participants? That is because of the power of a signature. Many people in this forum are whales holding a lot of coins and they can contribute a lot if they find the project interesting. Also some researches have been conducted that showed that when you continuously expose someone's sight to a particular stimulus for a number of times, it greatly affects their subconscious and they easily patronize those things (that is what they do on TV commercials). So wearing a signature doesn't mean that they will just be displayed under posts , but it really has a great impact. Another thing we can consider is that, making a project successful also needs large community participation and bounty sign ups. Many bounty hunters discover projects through people who wear signatures. So in a nut shell, a signature is really important for project promotion!!