Twitter just released the twitter lists feature which makes a great impact within few minutes on the micro blogging social network considering the advantages in the lists made manually It makes marketing the right product to the right people with no big effort ! This is a boon for all twitter users (both social and business birds)
Pretty ironic since I had just signed up for Brizzly, which offers categories as its main benefit over twitter. They are smart in pushing that feature to keep users on their site, considering all the apps out there that allow the same thing. Seems these days if your site is API based and not that feature rich, people will make other apps to make your site work more efficiently, albeit remotely from the app so its hardly even the same site anymore.
I've had Twitter list a few weeks, a great improvement IMO Here are a few I've made so far vBulletin - IPB - Social Media
Just discovered lists and trying to get my head around them. Seems good idea and ability to target market is def a good idea.