In those 2 years, we've learned a lot. Our initial inspiration was Salesforce.com, which launched trust.salesforce.com to show uptime about 2 years ago. Though in fact, the tracking there is actually somewhat limited, with outages less than 15 minutes, and scheduled downtime, not tracked. Google for example only just followed with Gmail and Apps uptime status in the past few weeks.
We've gone to the extreme since early 2007, with 2 years of full data, including scheduled downtime.
Why? The simple answer is because we had to be. Closing deals, signing contracts, is a mission-critical business process.
You have the right, and should demand, full transparency from all SaaS and web services vendors for the applications you depend on. Almost no web-based application can truly deliver 100% uptime, 24x7x365. But you deserve to know in real-time if there are issues, and historically, what the issues have been, why they occurred, and how they were addressed.
"Success is built on trust. And trust starts with transparency."