I like what Cory Doctorow had to say on information overload and the shelf life of interesting content:

It turned out that “overload” has a wonderful corollary: redundancy.

Anything really worth seeing wouldn’t just appear once and vanish. The really interesting stuff would find its way into other discussions, and early conferencing systems made it easy enough to back my way through the forums I was ignoring or skimming to find the important thing I’d missed.

The online “echo chamber” gets a lot of flak, but one thing it does well is ensure that interesting stuff never really dies.