Look Now, Before This Disappears!
I was reading an entry in (it's the end of the world as we know it) andifeelfine.blogspot.com and was moved to search Google for the lifespan of a housefly. No, I didn't find the porn site, but I did find this entry at a UCSD website, which referenced the launch of the UK Web Archiving Consortium. The Consortium issued a statement which began as follows:

For many, the web has become the information source of first resort. From keeping abreast of latest news and accessing online journals and datasets, through to finding information about travel and sport, the web has become the information tool of choice.

However, despite our apparent dependence on this medium very little attention has been paid to the long-term preservation of websites. Indeed, with the life of an average website estimated to be around 44 days (about the same lifespan as a housefly) there is a danger that invaluable scholarly, cultural and scientific resources will be lost to future generations.

I've forgotten the math that I barely knew, but it's clear that there is...

(excuse me while I throw the tennis ball for the dog)

...a lot of variance in that "average" figure. While some commercial pages disappear within days, personal pages remain forever or until the host files Chapter 7.

Example: here's something that I signed back in 1998. (Ironically, I just realized something, but I can't say what it is. I don't want the pizza folks to get on my tail again.) This page is probably going to remain forever.