The following are the pros of using web analytics and customer support logs:

• They are readily available, often easy to get, typically require relatively little time to review, and are free
• Often, they are summarized and organized by the department that, optimally, is staffed with knowledgeable domain experts; if not, this item is a candidate for the cons bucket
• The records are forensic evidence of actual interactions, issues, and resolutions
• The records are quantitative, reflecting trends and patterns of use, that often are relevant to the new design