I often see e-commerce sites with a flow like this:
- You add a product and are automatically take to the shopping cart
- You click "Proceed to Checkout" are taken to a page where you give your shipping and billing information
- You click continue and review to see all that information again
- You click "Submit Order" to actually pay
What is the purpose of the third step? I figure we'd want to minimize the number of steps it takes to place an order. So there must be some advantage for those sites to put an extra step between giving your payment information and actually charging you.