Der Spiegel has pointed out (in German) some new research (PDF)about the lifespan of news items on the web.

The wonderfully jargon-heavy abstract of the study, which looked at the Hungarian news portal Origo, says it all:

… [W]e investigate the dynamics of visitation of a major news portal … The nodes of the network can be classified intos table nodes, that form the time independent skeleton of the portal, and news documents. The visitation of the two node classes are markedly different, the skeleton acquiring visits at a constant rate, whilea news document’s visitation peaking after a few hours. We find that the visitation pattern of a news document decays as apower law, in contrast with the exponential prediction provided by simple models of site visitation.

… [O]ur results document the fleeting quality of news and events: while fifteen minutes of fame is still an exaggeration in the online media, we find that access to most news items significantly decays after 36 hours of posting.

Presumably, this applies to most blogs too. Push technologies like RSS readers are probably also helping maximise this effect by encouraging readers to read posts as they pop up.

(Combining this knowledge with the observation that accesses to most big sites drop off markedly over the weekend, it’s probably smart for small bloggers to write on Sundays and post on Tuesdays to maximise visits.)

German blogger Raben Horst wonders why online newspapers hide archives that nearly nobody is reading behind subscriber walls.

It’s an interesting point. Presumably the value of news sites’ content decays in line with the falling demand for an individual story documented in the study. Meanwhile, real costs to the news organisation increase in the other direction as the growing archive demands more and more storage space, which in some cases might outpace the decreasing cost of storage.

So why seek payment only to the least valuable assets on the site? Online economics are wierd, though. Am I missing something here?