Official Google Enterprise Blog: Why the City of Los Angeles chose Google

By ITA estimates, Google Apps will save the city of Los Angeles millions of dollars by allowing us to shift resources currently dedicated to email to other purposes. For example, moving to Google will free up nearly 100 servers that were used for our existing email system, which will lower our electricity bills by almost $750,000 over five years. In short, this decision helps us to get the most out of the city's IT budget.