I’m not sure its fair to say “You still pay for upgrade, backup, SSL, and SPAM filtering.” You’re STILL paying for it in cloud based offerings. The advantage of the cloud is that the provider achieves certain quantities of scale, and passes the savings along to the end customer. Moreover, the labor and uncertainty associated with performing maintenance tasks is reduced or eliminated, by virtue of having a SME engaged in the tasks at hand. Instead of having an Exchange expert on staff, or paying VAR rates for support, you have the benefit of the expert working at the data center, with his costs rolled up into a convenient, easy to budget monthly fee.