I think it's important to realize that Mark's relationship with his audience is the MOST important factor in an idea that mean to use him as a platform for exposure.
Losing the trust of his audience by appearing to have "sold out" by filling up his videos with what is essentially advertising would turn off his fans and lose their trust. Mark knows what he's doing. Let him manage his fans.
The exposure he brings when GSL is in full swing will be amazing. But I do think it's important to be careful with about turning him into an ad man. He's not an ad man and his fans don't want to be fans of an ad man.