As Marketers we struggle between asking all the questions we can and getting no response and asking a few questions never being satisfied but getting more results. In this test below the desire to understand the customer location and industry was tested against a simpler form with just contact information.
Form (B) had a 5% increase in conversions. This test will vary widely depending on the usability of your fields. For example choosing a country and placing your dominant country in the middle or bottom will get users frustrated. Having Industries missing or two narrow causing users to want to choose more than one etc.
There is another solution which is to get the users information later in the sales process and ask no information up front. This example (C) had a 50% download rate! That means for every 1000 visitors 500 downloaded. However you will need to have systems in place built into your software to bring users back to the site and when then purchase to step them through a funnel process. The good news is by the time a prospect has used your software and wants to purchase they are more willing to provide information.