What are you willing to pay for availability?
Dan Farber writes up an interesting piece on Salesforce.com's rather extended scheduled downtime. In the process, Dan quotes a fellow Enterprise Irregular Charlie Wood who says:
Does anyone think PayPal could have hours of scheduled downtime and get away with it? Of course not! Why not? Because payment processing is a mission-critical, 24×7 function. Shouldn’t sales and support be no different?
In fact it should be different. People are prone to forget that sales force automation has very little to do with actually securing revenue. If your SFA is down, you may not be able to enter some contact information or update your pipeline, but this is hardly life threatening for a few hours. By contrast if your order entry & fulfillment system goes down for a few hours, you are likely to experience some serious commercial consequences.
None of this is really a SaaS topic. It’s more a matter of not paying for mission-critical availability for a non-mission critical system. For an extra $5/user/month I imagine Salesforce could substantially reduce downtime. But for most customers would prefer to save the money and do without a contact management and pipeline tracking system for a few hours a week. If you were making this same decision for a manufacturing execution system or an order entry system or a telecom OSS system, you’d make a different decision.
There have actually been mission critical systems available as a service for decades now. Payroll through ADP is one example. Also many small community banks get their highly mission critical payment systems as a services from larger banks that can afford to maintain the infrastructure. They just come with mission critical prices.