At the initial signup, you don’t want to scare people off, so you only request the information you really need. But after the relationship’s established, it’s smart to go back and request more information from your email subscribers:

• Get or confirm opt-in status
• Gather information for more granular database segmentation
• Collect additional data for personalization
• Request additional contact information for other channels

This week Clickz is featuring an article called "Know More About Your E-Mail Subscribers" in which Jeanne Jennings gives a few very good tips for getting more information from your e-mail list members.