During the second half of 2004, Netcraft measured the reliability of 50 leading webhosting providers websites. At first sight this appeared to be a totally meaningless measurement since it doesn't say anything about how they manage their customers websites. Their own website could very well have a server for itself while they are overloading all the servers their customers websites are on. And it's the availability of their customers websites that matters to customers.

The (just a little) interesting part is that Netcraft measured the uptime from 4 different access points and noted all failed requests. Assuming that the hosting company's website is hosted at the same physical location as their customers' websites in this says something about the reliability of the network that will make your website available to the public.

You can read the results here and there is also some interesting information on the page that explains the measurements including that Netcraft charge 1200 GBP per annum for inclusion and that companies located in the US have an advantage over companies in the rest of the world.

In other words, you can safely ignore this Netcraft survey while investigating your next web hosting provider.