Microsoft has announced five data centers in the past 12 months, including in San Antonio, Tx., Chicago, Il. and Des Moines, Ia. Both its Chicago and will be massive, $500 million facilities that will have many of its servers pre-configured and .

Investing in a big way now, Microsoft has argued, will save money later.

Demand for some services is already huge. Microsoft's Monday has more than 450 million unique users in the system, passes more than 8.3 billion messages and performs more than 1 billion Web authentications a day, said Ravani.

Besides touting the scale of Microsoft's cloud infrastructure, Ravani also touted the resiliency of its network, which he said was the result of several hard-earned lessons.

For instance, in November 2006, half of a million users of a Microsoft online service experienced authentication delays for several hours. The problem was an overload of the authentication system caused by a poorly-written internal batch job. As a result, Microsoft created a policy that all batch jobs need to be tested first, and increased security, so that users can't access key data services without authorization.