I want to setup conversion tracking to track whenever a user clicks the buy it now button my webpage. I am a little confused how I would setup the javascript code so that it executes only when someone clicks the buy it now button. Any pointers would be appreciated!
If your using paypal IPN, you can place it on the page that the user will see once they return to your site. I'm assuming you have a confirmation page?
You could also create a page between the landing page and he "buy now" page that redirects to the buy now page after a few seconds. You would put the code on that middle page and record how many people click on your "buy now" button. Not sure if you can do this with PayPal. PayPal should definitely look into allowing users (the smaller ones anyway) to integrate the system more into their site and allow for stats to be collected.