Do Web Enhancements Pay Off?
http://www.allen.com/cgi-bin/gt/tpl_page.html,template=1&content=23&nav1=1&

Allen, Cliff
Allen.com
2001

Abstract:

It's commonly thought that investing in loyalty-building features such as personalization is a sure-fire way to increase profits. This is because it costs less to keep a customer than to attract one in the first place. However, a deeper look into the economic value of Web site enhancements might have you changing your priorities.