It struck me yesterday as I watched my wife surf eBay and eBay-related sites (like DisturbingAuctions.com) that eBay et. al. functions as a vast weblog for some people the same way that “traditional” weblogs function for people like me. Or more precisely, eBay fills the same needs for some people that weblogs fill for others.

(What needs? Well, the first thing that pops to mind is social needs, the kind of social needs you find satisfied by participating in an online community of some sort.)

Probably this has been obvious to many people long before I realized it. But this metaphor of eBay-as-weblog (or perhaps more than a metaphor) has been staying with me, nagging around the back of my mind, so I figured I’d put words to some of the ideas and see what comes of it.

It might be more fair to say eBay can be considered a meta-blog, categorizing and listing the individual entries (auctions) of thousands of bloggers (sellers) (side-note: perhaps eBay is more like an aggregator?), providing means for users to comment (feedback, ratings). Popular auctions are peer-reviewed and the cream rises to the surface, much the same way as in the weblog world.

It would be trivial to graft typical weblog services, like RSS, onto eBay’s services. I’ve toyed with this idea before, I think it would be a great example of the killer app RSS wants to be.

But it makes me wonder: why doesn’t eBay have RSS feeds? They already offer a saved searches feature that emails you notifications when new items appear matches your search criteria; that should be a no-brainer for a feed. Or perhaps feeds to supplement the services that many third-party sites offer: collective views of items you’re selling, with current hit counts and bid prices.

One problem I do foresee, though: eBay is highly time-dependent. Users want to know what’s happening with auctions now, via a browser refresh or an up-to-the-minute email; RSS as it’s implemented now is not enough of a “push” technology to make this happen. Sure, you could fake it by setting your aggregator to poll eBay every 5 minutes for a feed update, but what happens when 100,000+ users retrieve an XML file 12 times an hour? Bandwidth dies, of course. EBay would brown-out.

Anyway, that’s enough for tonight. I’m still finding the eBay/weblog idea intriguing; I may try to merge both worlds and produce some sample RSS feeds based on eBay searches. If I do, I’ll post them here.