As Schachter says of del.icio.us, "Each individual categorization scheme is worth less than a professional categorization scheme. But there are many, many more of them." If you find a way to make it valuable to individuals to tag their stuff, you'll generate a lot more data about any given object than if you pay a professional to tag it once and only once. And if you can find any way to create value from combining myriad amateur classifications over time, they will come to be more valuable than professional categorization schemes, particularly with regards to robustness and cost of creation.Valuable to whom? In other words, Shirky is saying amateur contributions are more valuable than those of paid lackeys when it comes to manufacturing meaning, a process that can't be managed within traditional capitalist factory conditions. Meaning-makign is immaterial labor; Web 2.0 is the infrastructure that can harvest it and subjugate it to existing capitalist relations.
Shirky extols the values of doing away with ex ante taxonomy (which he wants to call ontology for some reason) and replacing it with filtering both passive and active. The presumption is we should always begin with too much information and whittle down to what we deem necessary. But the problems with that are obvious if you consider that producing too much information has become the most successful strategy for hiding secrets in a thicket of data. There is little chance our filters will yield the disguised secrets; but it will satisfy us enough to keep us from looking for secrets, from imagining that they exist.