Ever wondered how your buyers found you and your stuff? Sure you did. And do. So do I!
And I've discovered that there's an optional question you can add to your Paypal checkout that asks your buyers exactly that: How did you find me?
The question is entirely optional and will appear at the end of purchase while your buyer is paying. It's super easy to set up, too!
1. Login to your PayPal account
2. Go to -->My Account -->Profile
3. Selling Preferences --> Custom Payment Pages --> Options --> Merchant Service Options
4. Check "Add a Customer Service Survey" and fill in the blanks with the choices you'd like to offer, i.e. Etsy, Blog, Twitter, Facebook, Friends