I am a regular participant in signature programs and I find that they do not help projects. The signature program is inferior to Twitter, Facebook, Telegram, Youtube Video ... because it only affects the Bitcointalk forum. Other social networks have more users and certainly bring more advertising value.
In what you wrote, there is a place to be, but partially. The bitcoin talk forum effectively promotes projects through signatures. First of all, this is due to the profile and narrow focus of the forum. It discusses the basics, development and promotion of projects by people who have knowledge since the inception of blockchain and cryptocurrencies. Therefore, social networks are thieves in importance.