In 2002, InfoWorld gave a Technology of the Year award to "publish/subscribe" technology. In the writeup (registration required) I mentioned Kenamea, KnowNow, and the Flash Communications Server. The del.icio.us bookmarking system has some of the pub/sub flavor of those systems, as well as some of the blogging flavor.
In the blog network, you publish to a personal identity (your own), and you subscribe to other people's identities. In systems like KnowNow and Kenamea, people (and also applications) publish to, and subscribe to, topics.
Consider the del.icio.us tag e4x, which I created today to help me keep track of this article on a subject I expect to learn more about soon. At the moment, my e4x page and the systemwide e4x page are the same: mine is the one and only use of that tag.
Even if I'm the only one to collect e4x references by means of that tag, it will have value. I'll be able to access a set of bookmarks from anywhere, and easily share them. Things could get more interesting if other people's e4x references start to show up when I visit (or subscribe to) the tag. Whether del.icio.us (or an analogous service) will reach a scale that makes that likely, for specialized as well as common terms, is an interesting question.
Once a tag does reach critical mass, another interesting question arises. Do you monitor the global view or do you rely on one or more user-filtered views? I guess the answer is both, at different times. When a tag is new and receives little traffic, watch the whole thing. If traffic grows too heavy or too noisy, interpose trusted human filters.
Former URL: http://weblog.infoworld.com/udell/2004/08/13.html#a1059