We believe the context we provide is a much more valuable use of the limited sidebar space than the ads it replaces; and we think that adds value to the platform, both for Google and for its users. People evidently agree, as (nearly) nobody complains about the loss of the ads, but lots of people love the utility we provide - and indeed have switched to Gmail to get it.

We're not interested in cheating Google out of their ad revenue, although we suspect the Gmail ads aren't making that much revenue anyway.

We have a good relationship with Google, and we were a launch partner for their contextual gadgets platform: http://googleenterprise.blogspot.com/2010/05/putting-email-i...