eBay is fairly clearly the exemplar of the network effect (Fool.com) - all the sellers go there because all the buyers are there, and so on ad infinitum. Boso may have found a chink in the eBay armour.
Boso, says Trendcatching, is a new auction site that targets UK students with various advantages:
"If you trade with people within your university there's a number of advantages over conventional auctions, including greater trust, the ability to exchange the goods in person, as well as more relevant items for sale e.g. text books from the same course."
Perhaps Boso had identified a real niche that can be persuaded to migrate en masse from eBay, thus breaking the defensibility of the network effect.
What isn't clear to me is whether the benefits of trust, relevance and convenience are enough to outweigh the downside that a smaller pool of buyers (than, for example, on eBay) will on average mean a lower price. Probably the marginal difference is often less than the postage costs and listing fees involved in using eBay, especially on small-ticket items like textbooks. Then again, the pool isn't just smaller - it's also poorer. Students may be almost the only market for second-hand textbooks, but with their generally limited disposable income they're less likely to be the ideal market to maximise the auction price of an iPod or laptop.
(The other thing about Boso that piques my curiosity is whether it will tell us anything about the relative fortunes of students at different universities. Does the site make it easier to watch the flow of second-hand iPods from Oxford to Hull? Not sure yet, but it's a vaguely interesting social experiment.)