By John Bowman, CBCNews.ca

Last week, the New York Times Bits blog wrote about Twitter's switch from TinyURL.com to bit.ly as its default URL shortener, the service that provides shorter URLs for web pages so that they'll fit into a 140-character tweet.

I linked to the post on @CBCtechbytes and got some sarcastic feedback about this earth-shattering news. After all, what does it matter which service Twitter uses? There's no difference, other than five or so characters you save using bit.ly, right?

Well, there's a lot more to bit.ly than just a shorter URL. Add a plus sign to the end of any bit.ly URL and you can see traffic data about that page, updated in real time. You can also see a list of tweets that use that URL, so you can keep track of how a link is spreading around Twitter.

At the bottom of the bit.ly info page is a collection of metadata about the link, including title, summary, and a list of "entities" that appear in the article. An entity can be just about anthing: a city or country, a person's name, a company or product, a computer operating system or programming language.

This metadata is very useful if you're indexing information for search, which, according to CNet, is exactly what Twitter's planning.

The metadata is generated by a service called Open Calais, which is owned by Thompson Reuters, and the terms of service for Calais reveal who owns all this powerful metadata that Twitter is generating:

You understand that Thomson Reuters will retain a copy of the metadata submitted by you or that generated by the Calais service. By submitting or generating metadata through the Calais service, you grant Thomson Reuters a non-exclusive perpetual, sublicensable, royalty-free license to that metadata.