interests
What do your customers do for fun? What are they interested in?
If you discovered that 80% of your customers were interested in golf, how would you change your messaging? How would you change your advertising platforms?
demographics
Do your customers own their homes or do they rent?
If you knew their income level, marital status, number of people in their household, etc., how could you leverage that to improve your marketing?
online behaviors
What websites do your customers visit? How do they spend their time online?
If you knew what your customers did on the Internet, how would that effect your media buys and placement?