Twitter has been aunching a slew of new functionality recently, most notably Twitter Lists. I say most notably because Twitter Lists addresses one of the most pressing problems with using Twitter.com as a primary Twitter client. It's very easy to follow so many people that you wind up really following no one. People's tweets just get lost in the stream.
Until now, I've solved that problem with 3rd party apps like Seesmic on my desktop and Tweetie on the iPhone that allow me to create groups of followers so I can filter down tweets to a manageable thread and actually keep tabs on the people I'm most interested in. Twitter Lists, however, allows me to do that right on Twitter.com and even better, share those lists with others. The lists I aggregate can become little tidbits of value I share with the masses.
That's really relevant to brands seeking a meaningful metric for how to measure the success of their social marketing programs. Just acquiring followers is really quite meaningless. It's relatively easy to do (follow a bunch of people and some subset will jus