[Note: CNET sucks because they supported SOPA.]
Article worth reading, although I don’t think they really follow-through on the premise of the title — their conclusion on how to “do freemium right” is kind of light in details.
http://reviews.cnet.com/8301-19512_7-57615149-233/how-to-do-freemium-right/ – How to do freemium right
[PS – Did I mention CNET sucks? That’s why I didn’t make an active link — if you want to read the article, copy/paste, please.]