503 Service Unavailable Status Code Can Kill Your Search Traffic

This is a post I am sure the "Andy Beard Haters Club" will gloat over, but as I haven't been able to find a resource anywhere on the effect extended use of 503 Service Unavailable can potentially have on a site, and in particular the effect on search traffic, I thought I should write about it. [caption id="attachment_1794" align="aligncenter" width="500" caption="Using 503 Server Unavailable For Extended Periods Can Kill Your Search Traffic"][/caption] This isn't your typical scenario - 503 errors are frequently sent when a server becomes overloaded, or there are some backend problems. A search of the Google Webmaster Help forums doesn't bring up a huge amount of cases, and mostly it is enquiring about what someone should do when they want to do some maintenance on a live server, probably for a short time. In my case I didn't plan to be in "Maintenance Mode" for an extended period. Here is the complete timeline: