Five Ways To Make Sure That Users Abandon Your Forms
http://www.egmstrategy.com/ice/direct_link.cfm?bid=FBCF08E7-DEE8-F2D5-48AEF8A07371777B

Meyer, Eric
Improving Customer Experience
2006

Abstract:

What do you really need to know in your form process? Be brutal. Don't include stuff that your sales team would like. Completing a form is rarely (if ever) the goal in and of itself. The goal is to entice the user into a deeper relationship (of some sort) with your web site. Notice that I didn't say that the goal was to complete a transaction or make a sale. That is evidence of the deeper relationship, not the vehicle by which you persuade your users.