Adding Advertisements to Graal?

[Freudian_slip]

So I was thinking, games like Runescape use to make all their money on advertisement, right? Like, they were paid to advertise bull**** while in their game. Well, couldn't graal do this as well, but rather than putting it all over the screen and crap, just add billboards like Era use to haev for Era Business except they'd be real businesses. Along with this we can fill up some random buildings around Era with real life businesses that when you grab an NPC it sends you to their site or something? This would work pretty well on Era atleast considering it's modern anyway.

Would Graal be able to make any money this way? I honestly don't know much about advertisement.