People always talk about 99% uptime being important, but rarely do they think about what goes into making a web host reliable or for that matter what 99% uptime really means.
If your web site really had 99% uptime for the month of July your site would be offline for a total of 7hrs 26min. For an entire year this is 87.6 hours of down time. Is this really acceptable to you? It isn't to me; I'm looking for several nines after the decimal point.
There is a lot one should consider when choosing a web host that most people never think of. I discussed this in another thread so rather than rehashing an old post I'll simply link to it here:
Tips on How To Select a Reliable Hosting Provider
An article I wrote on this subject awhile back is:
http://klbproductions.com/resources/hosting.html