Check that you are clearly telling your visitors what you want them to do. Make sure you are saying things like, 'Click here to buy now', 'Do this to sign up now' or 'Click the 'Add to Cart' button to add this product to your shopping cart'. Make sure you close the sale. Many websites don't have a clear 'Call to Action'. Make sure your website has very clear 'Calls to Action'. The clearer the better!