Now sig spaces avails you that opportunity of exposure on a wide scale, now it is understandable that, users based on activeness and where they stand as per reputation on the forum have some level of influence more than others. You can always find people to be closely associated or agree on their opinions. This is the idea that backs up hiring these users signature spaces.
Wearing your brand is one way of portraying it to be good. You would need that and that’s why campaign managers and a few that wishes to go viral on good notes seek such users. You get to work with users based on agreeable terms and they advertise your brand using acceptable means.
You’ll find this in the service boards and even have managers to aid your purpose.