Stumbling after Stumbling upon StumblingUpon

A few months ago I, ahem, stumbled upon StumbleUpon, which I learn has just joined the growing dotcom 2.0 feeding frenzy with some six-figure angel funding.

The idea behind StumbleUpon is simple: you rate pages that other "stumblers" have found and recommended. This feeds back into the pages that are fed to you, as do other pages that you've stumbled upon independently, and rated. All standard social software stuff, with a hint of Google's PageRank thrown in for good measure.

It's a great displacement activity, and when I first stumbled upon it I spent some time wandering around other people's stumbles. Some were genuinely interesting, but as time went on, despite all my approving and disapproving, there weren't proportionately more sites that interested me, just a constant succession of occasional pages that on their own would have been mildly amusing. Ultimately it seemed that there was no pattern in the carpet, just more and more stuff - a kind of drip-feed Digg.com.

Maybe the novelty of stumbling wore off, but I fear it is something deeper: that it's not a very efficient way to find matter that is really of interest - as opposed to vaguely entertaining. For that, the usual news channels - and a judicious selection of hard-working blogs (like paidContent, whose posting told me about StumbleUpon's company of angels) - seems a far more reliably productive way to gather information and sites. To say nothing of Google's PageRank, or even Digg.com - which you can at least skim-read very fast.

So who's stumbling here: me or the stumblers?