I’m taking Rojo for a spin, mostly because of recent upgrades that add some interesting features, including a “sort by relevance” function that lives alongside the usual “sort by date”—a “personalized digg”, as some have called it.

One thing I like about Rojo is that it’s a River of News style aggregator, which means all feeds get combined into a single stream that’s very easy to scan for interesting items, rather than serving as just another way of filling my inbox with stuff I won’t have time to read anyway (the “aggregator as an extention to the email client” model).

With River of News style aggregators, it’s no big deal if you miss something, kinda like it’s no big deal if you don’t read every last article in the newspaper every morning.

Trouble is, how do you make sure you read the most important stuff first, so in the event you don’t get through everything, the likelihood you miss something is small? “Sort by relevance” would appear to solve this problem nicely.

Rojo appears to calculate “relevance” by analyzing a few things: What I read (i.e., what I click on), what I tag (either by giving it “mojo” or by tagging it in the Web 2.0 sense of the word), and what my contacts read and tag.

That seems like a reasonable enough algorithm. Problem is: 1. most of the things I read Rojo doesn’t know anything about (they’re in my browser clickstream); 2. I already have about a year’s worth of tags accumulated at del.icio.us, and I have no intention of moving those tags anywhere else (ironically enough, because del.icio.us gives me the ability to do just that); and 3. I already have more social networks and contact silos than I know what to do with, and I certainly don’t want another one.

So, Rojo’s new features are less interesting than they appear at first glance. Guess I’m going to have to continue doing without, either until I decide to dump all my stuff in one place (ahem) or until small pieces loosely joined evolves a bit further.

Update: On second look, it looks like relevance is actually calculated by the total number of reads and tags rather than by the number of reads or tags by me or my contacts. Not sure how that can be called personalized, but I guess those are the words of others, not Rojo’s.