I can tell you what happens because it happened here earlier in the month and it was partially my fault. You simply panic. I can also tells you what it does to your momentum it slows it down. The 3-4 days I was having trouble caused my site hits to drop by nearly 20% the initial week after the recovery. Only now are we back to pre-blog blackout days.
How do you mitigate it if your running your own site. It’s called redundancy. I have two dedicated severs now and both of those boxes are going to have the data from each mirrored on the other and both now have the DNS propagated in way if one goes down the other can take over very quickly. We will only be risking 24 hours of data as we are shipping the databases to each box each night.
But if you are on a hosted service that you cannot touch your kinda screwed. A large number of Typepad users where without service for a few days and let me tell you I felt your pain. I thought I was going to have a heart attack before I got my sites back online. It was terrible.
If you blog is serving data thousands of visitors a day spend a little money and put in some safeguards. [gigaom.com]