I've joined in order to be able to display the seal on my own ecommerce site. As a single-person company, it isn't terribly expensive (it is priced per employee).

I don't have any hard evidence (such as an A/B test) to support my decision, but I'm selling monthly subscriptions to businesses and felt the impression of credibility was worthwhile.

I belong to the BBB so that I can have their logo on my site. I thought it was expensive since that is all I want of them.

It frustrates me that scammers such as Video Professor use the service.