At the end of the day, they're all likely to fail. Provided of course that you know how to setup and maintain a server (farm) in the first place. If you don't

At the end of the day, they're all likely to fail. Provided of course that you know how to setup and maintain a server (farm) in the first place. If you don't, you have no business being a SaaS provider. However, when your own servers fail, YOU can generally react faster than when someone elses server fails, and you rely on them to fix the outage and get you back online. This is especially true for SaaS startups. When Rackspace had their issues last year, and had to shutdown "some" servers because their datacenter was overheating, who do you think they shutdown? The startups with 2 or 3 servers, or the BigCo's with 2 or 3 full cabinets?