Nobody except the creator that is. Which is quite discriminatory, yannow... and lends itself HIGHLY to deception.

Scenario 1:

Honest merchant A: I have a new product elsewhere, but I can't advertise it at Rendo. Oh, well.

Scenario 2:

Dishonest merchant B: I have a new product elsewhere. Hey, buddy, make a thread for me!
Buddy C: Of course! And make it not look like blatant advertising, right?
Dishonest merchant B: Of course! Now get on wit yer bad self!

The idea of an "Offsite Merchants" gallery or forum is the best one to date. Or you could actually learn what COMMUNITY means, and get rid of this rule. I closed my Rendo store last year about this time for more and more niggling little things. This alone would have made me close it.

Remember, kids! Napalm is Nature's Toothpaste!