chewy - 6:27 pm on Aug 20, 2012 (gmt 0)
Here's a different approach - it could be that you are attracting people without the ability to buy online.
I see this a lot. I call it the "kid problem". What I see often is that many visitors are very young children doing research for one reason or another to educate, amuse themselves, come up with things to say to others, etc.
See if you can figure out what the average age is of your visitor in some kind of exit survey or contest or something.