Some books to start from

* Anderson, Chris: The Long Tail

http://www.amazon.com/Long-Tail-Future-Business-Selling/dp/1401302378

http://longtail.typepad.com/the_long_tail/

http://www.longtail.com/the_long_tail/2008/01/what-does-the-m.html

http://leighbureau.com/speaker.asp?id=373

See discussion about long tail phenomenon:

Elberse, Anita. "A Taste For Obscurity: An Individual-Level Examination of 'Long Tail' Consumption." Harvard Business School Working Paper, No. 08-008, August 2007

Elberse, Anita, and Felix Oberholzer-Gee. "Superstars and Underdogs: An Examination of the Long Tail Phenomenon in Video Sales." Harvard Business School Working Paper, No. 07-015, 2006.

* Hamilton, James T. All the News That's Fit to Sell: How the Market Transforms Information into News
http://press.princeton.edu/titles/7604.html