IDG Answers is a community of experts who are passionate about technology. Ask a question or answer one below.
If the right infrastructure has been put into place, a server instance or even a server farm outage won't bring down your website; the trick is to have load-balancing installed in such a way that if one server instance or server farm goes out, another one takes up the slack.
You might want to check into check out Cloud.com. They provide private cloud hosting services and were just purchased by Citrix, so they're probably a fairly reliable company as well.