To get back to a prior question you asked (which I did not answer it seems) as to why banning advertising would protect incumbents, it's because people already know about them while they wouldn't know about upstarts. Again with the Coke example, a new soda brand would find it exceedingly difficult to gain a foothold if everyone simply defaults to Coke normally. Same as in software, imagine if a new search engine competing with Google came about, but since everyone already uses Google and since the new search engine could not advertise themselves (with such a ban as yours), they will likely fail, even if their product is superior.