But ultimately, if I didn’t feel confident that I could assess empirically the good I was purchasing, I would not buy it on eBay, even if the seller had great feedback. At least for me, the risk is simply too high. That’s why there are many items I would never buy on eBay.
The full article goes beyond product authority, but the beginning does a great job of identifying the key characteristic of 'product authority' - whether two items are equivalent. When two sellers offer something, there is great value in knowing that it is the same thing. This enables several capabilities - price comparison for example. Of course, sellers don't particularly enjoy competition and you'll find subtle differences in many nearly equivalent products. Over the holidays we had four families in our house, and each of us had the same camera - which made it easy for anyone to pick up any camera and take a family shot - except the model number was different and some minor features were different. This separation based on product authority enabled a capability that is of interest to seller - differential pricing in order to capture the consumer surplus.
In the ontology (there's that word again) of selling, there are two main branches 'goods' and 'services'. Product authority so far has dealt with goods, and the ecommerce industry's expansion into services poses questions that the Corante article discusses. Check it out.