Is it? What are Google up to? Why should they shell out money to publishers for making users try Firefox? What's behind all this?
My guess: Google is very aware of the increasing/upcoming competition with Microsoft (with regards to search and AdSense), and they want to weaken the market position of Microsoft. Just costs them a few Dollars. So far so good.
But is this in the interest of Adsense publishers? Shouldn't we look forward to a strong and healthy Microsoft that is empowered (as good as it possibly gets) to take the fight with Google?