Google's new offline ads encouraging IT administrators to switch to Google Apps show just how serious it is about going after Microsoft for enterprise business.Andy Berndt, managing director of Google Labs, notes that over one-and-three-quarter-million businesses, schools and organizations "have gone Google -- including Motorola, University of Notre Dame, [and] the Mercy Corps... and each day, 3,000 more organizations join them."

Google is going about this in a very systematic manner, and is doing a lot more than just throwing Microsoft a brush-back pitch or forcing it to divert resources. Google is in this to win.

Here's a few areas where Google is attacking Microsoft:

Google claims to have plenty of large enterprises switching (or considering a switch) from Office to Apps, but can oddly only mention a limited number. Is it an issue of NDAs, or just that very few large enterprises are actually switching?

Maybe it doesn't really matter -- Google knows from experience that some small companies eventually become big ones, and if they're already running Google Apps, there's no reason to believe they'd switch to Microsoft when they grow up.

This won't happen overnight either -- as Fred Wilson notes, legacy technology dies slowly.