I was travelling a bit this weekend, to my old college town of Williamstown, Massachusetts. While there I met up with many friends, most of whom asked what I like to do in my spare time. Which led to me explaining frassle, in pretty abstract terms, to a bunch of smart people that weren't all familiar with blogs.

While explaining frassle five times in a day isn't exactly continuous entertainment, it did let me get a few interesting, big-picture perspectives on frassle. Which got me thinking: where could frassle go? Dreaming big now—what ideas that are in frassle today could grow into major new kinds of tools and services? Here are a few answers.

1. The most accurately targeted advertising ever
Frassle defines shared understanding in a computable, measurable way. It can quickly give you an explanation of what one of my categories means, delivered in your own terms. It can probably be scaled to do this across multi-level social networks. To the point, frassle can give you a pretty good idea of who (among a very large network) would be interested in a particular thing, given only a small sample.

That is exactly what advertisers want to do. Given a product, they want to make the people who are likely to buy it aware of how great it is. The nature of mass media favors advertising that pushes products almost everyone needs, because the message always goes to everyone. Products that are likely to be highly useful only to a smaller group of people are therefore underserved by mass media advertising. Google knows this and delivers a higher clickthrough rate on ads hosted through their AdWords program because they keep track of how successful different ads are on different websites.

Frassle's inter-category mappings would simply be another way to track the same kind of correlations. Since frassle delivers a publishing and authoring interface to individual users, not just to website with a box on the right for ads, you could even target ads based on data about the viewer herself, rather than the particular website she is currently viewing.

Could it work as well as Google's AdWords? Could it work better?

2. A personalized search engine

The same kind of data frassle would collect for targeted advertising would also make for a much smarter search engine. First, search could be contextualized for each user, based on their category structure and recent interests. Second, relevance data could be used to better rank search results. The right stuff, right at the top of the list.

3. Integrated knowledge management for workgroups
While it may be very hard to make all of frassle's features usable for the general internet-using public, it might be a lot easier to set it up within an existing organization. Companies have oodles of documents, scattered all over the place; they have oodles of people, struggling to communicate through overloaded tools like email and insufficient physical spaces; they have oddles of shared projects that ought to involve certain people but can't make those people aware they even exist. The ideas in frassle could help with all of these, and might find excellent uptake in a small, close-knit community of knowledge workers.

Is it scalable? When I first discussed the ideas behind frassle with Scott Johnson, founder of feedster, he seemed skeptical that it could scale enough to cover a significant part of the internet or even just the blogosphere. I have a lot of respect for Scott's opinion—he's been building search engines for a long, long time. So I know a system that tracks hundreds of category systems and thousands of inter-category relationships probably can't be scaled to millions and trillions just by adding off-the-shelf software. This is still the big question. Do we need a Google-style cluster of thousands of machines? Can we make it a distributed, peer-to-peer application?

Is anyone else doing this? Some related ventures are under way from Technorati, Amazon.com and A9, and certainly others. How do I find them?