James, (1) it’s theoretically reasonable to only store index information, but it doesn’t usually work in practice for serving a lot of users quickly and with a simple UI. (2) You’ve lost me. What gatekeeper? There’s already a lot of spam in Feedburner. All I have to do is get a bunch of bots to subscribe to the feeds and how are they going to know the difference? Google the feeds.feedburner.com domain for Viagra and guess what? Spam, spam, spam, spam…..

http://tinyurl.com/j8jdr

The Sphere It! bookmarklet is a very robust piece of technology, developed over several years by my two cofounders, Martin Remy and Steve Nieker.

Sphere It takes advantage of a novel text analysis technology that
analyzes entire document texts (a news article or blog post in Sphere
terms, but any text will do; the technology works just as well on
product descriptions, Word documents, etc.). Each text gets passed
through a proprietary pipeline that extracts key concepts and themes.
These key concepts and themes are encoded in a data structure we call
a Document Genome.

As the name is meant to suggest, a Document Genome is unique to the
text from which it was derived. It’s worth emphasizing at this point
that DGs are not simply keyword extractions. There’s a complex
analysis pipeline employing a number of both traditional and novel
text-analysis routines to identify the concepts and themes. The
tokens of the resulting Document Genome, in contrast to keywords, are
machine readable abstractions that don’t mean much to the human eye.

Like the biological data sets they’re named after, Document Genomes
can be compared for similarity. (I’m 98% chimp; 63% iguana!) We
generate Document Genomes for every blog post we crawl. When you’re
looking at a page on the Web and click the Sphere It bookmarklet,
Sphere grabs the text of the page you’re viewing, generates a
Document Genome for it on the fly, and compares it to the DGs of the
blog posts we’ve crawled. The closest matching blog posts are presented.

In practice, the Sphere It approach to contextual matching is
fundamentally different from other approaches out there. If you
compare it to other text-based approaches, like Google’s Similar
Pages or Yahoo’s Search Related Info, we’re consistently much more
precise in our matches.

Compared to other blog-space approaches, like Technorati This, Sphere
It! gives a wider breadth of results on the topic. Technorati This!
limits results to only those blog posts that link directly to the
page you’re viewing. How do you find the posts that were published
prior to the page you’re reading, but on the same subject? How do you
find posts discussing similar topics from other sources (you’re
reading WSJ, they’re reading NYT)? How do you find posts discussing
the topic but not linking anywhere? Sphere It makes those
connections. (I’ve covered this in more detail at http://
sphere.wordpress.com/2006/05/12/week-one-in-the-rearview-mirror/)

1. I understand the need to develop the index with some “tricky math” but i don’t believe the underlying content archive is an issue.

2. Totally agreed about spam finding any viable source. But Feedburner has a gatekeeper. The ‘index’ would not be formed around unknown pings from ‘naked’ feeds, they have the content centralized(Feedburner feeds only), and the goal would never be to ‘index’, in this case, the whole blogosphere. The ability to discriminate is key here.

3. Agreed

4. I am just going off what I have seen and read so far, which is admittedly limited. I guess the person to ask would be Tony.

1. What Feedburner has is probably not an index, it’s a directory with no (disclosed) underlying content archive. “Index” typically refers to having some sort of archive of the content and finding some tricky math to organize it. It’s only important to make this point as the lack of an index defines many of Feedburner’s limitations.
2. There is no reason to believe that Feedburner will be spam-free, or is even spam free now. If they turn into a complete and economic ecology (or if they organize their publishers into an index, see #1), the spammers will simply start running their feeds through feedburner.
3. You and Marshall are dancing around the right JIT search answer from my point of view, but are mixing two issues. Blog portal home pages are likely to be headline-driven a la Google News and the current ‘rati home page. The issue is that a search box is not suitable to setting up search feeds for 95% of the population. What is suitable is unclear so far.
4. How do you determine that Sphere is even loosely semantic in nature? Tony’s a good marketer, but it’s unlikely in the extreme.

Trying to subscribe to a search on technorati is nearly impossible, why? Because they don’t want you too. They want you coming back to the site, uploading your OPML(favorites?) there, and having your “watchlists” on site.

I think that Technorati’s newest announcement this morning is spot-on to where their product is shifting. They can sell syndication to content portals or the JIT alerts/communication relationship to the enterprise, like they are doing with Edelman, but for the average internet browser the play looks to be more and more like a blog directory/community.