When you're reading a message in g-mail, on the right there are buttons for things like "print" and "new window."
You don't have "sponsored links" under there that often relate to subjects found within your e-mail?
You're right. When you open an e-mail, you do have links to the right side. I never noticed that. However, in Docs, still no adds, no matter what you open...at least not yet.
I'm sure iWork.com will be awesome. But, I don't think it justifies another monthly bill for a service I can get for free. And even if Google did decide to place adds in their Docs, I don't think I would mind. Advertising is everywhere; in papers, magazines, TV, before movies, even on Macrumors. If it they invaded Docs, I would just accept it as a fact of life.