Sigs used to be a way to reward posters for their contributions by helping them to kickstart their own websites, or to make a political statement or personal opinion. Unfortunately advertisers started to buy signatures, and posters saw this as a source of income. It all went downhill from there imho.
That's because they wanted more visibility. Imagine what would happen if only the employees were allowed to wear clothes with a business logo. The owner would probably hire temps or pay people to pose as employees to get more visibility in the street. Paid advertising has existed before the signatures and will continue in this form or another.
