Gather as much information as you can about your users. Your users' demographic profile will give you a better understanding of the types of users your site attracts and how to satisfy their needs.
Here are a sample of questions that you need the answers to:
What is the gender split amongst your users?
What age groups are they?
How Web savvy are they?
Where do they mostly use the Internet; at home or at work?
What types of products, or services are they looking to purchase?
What kind of information are they looking for?
Where do they live?
What is their annual household income?
If you don't have any user demographic information, you can use existing market research data, or conduct your own market research to find out the information. The following links lead to some well-known Web sites in the fields of statistics and demographics.