Here are some posts that provide analysis:
http://www.avc.com/a_vc/2012/12/mba-mondays-revenue-models.h...
http://www.avc.com/a_vc/2012/12/mba-mondays-revenue-models-a...
http://www.avc.com/a_vc/2012/12/mba-mondays-revenue-models-c...
http://www.avc.com/a_vc/2013/01/mba-mondays-revenue-models-s...
http://www.avc.com/a_vc/2013/01/mba-mondays-revenue-models-p...
http://www.avc.com/a_vc/2013/01/mba-mondays-revenue-models-t...
http://www.avc.com/a_vc/2013/01/mba-mondays-revenue-models-l...
http://www.avc.com/a_vc/2013/02/mba-mondays-revenue-models-d...
http://www.avc.com/a_vc/2013/02/mba-mondays-revenue-models-m...
http://www.avc.com/a_vc/2013/02/mba-mondays-revenue-models-g...
They are all worth a read.