Most shopping carts have a print option somewhere in the process (before or after the order is complete). It seems like the lack of printing becomes more of a concern when you jump to PayPal to complete the order. But you're right, if everything goes as planned the details of the order are in PayPal and you should get an email confirmation. If you abort the payment, however, because you didn't have your credit card handy or forgot your PayPal log-in or any other reason, everything is gone and you have no record of your selections. Once you push "Buy Now" all your selections in jAlbum are deleted.
Maybe if you don't think a print is necessary you might consider prompting the user before deleting the shopping cart contents?? The prompt asking whether to delete the shopping cart could pop up after they push "Buy Now". Just a thought. I've had people push the "Buy Now" button while exploring the processes but not planning on completing the order yet. They end up losing their selections. I'm just trying to figure a way around that issue. It's hard when PayPal is in the mix and jAlbum doesn't receive a payment confirmation transaction from PayPal.
When users print out the shopping cart and finally cancel the payment process they might think the print is a proof or their order.
Perhaps warning users before removing the items from the cart would be a possible solution. What is your estimate on the proportion of users canceling the payment? Unfortunately, the skin cannot verify if the payment has succeeded or not (because the cart runs on the visitor's computer), therefore it will have to ask every customer if the cart can be emptied. Perhaps an option to restore the previous state of the cart would be less obtrusive for those who paid, so they don't have to act.
I agree that printing prior to completing the payment is not the best solution if someone's goal is to cheat the system. Printing should ideally occur after the order is complete but it sounds like jAlbum can't get the confirmation back from PayPal since it's not server based.
Regarding your question of the proportion of users that lose their selections because they didn't complete the payment, I don't have a firm number. I had one client mention it and I could certainly see why it could be an issue. I know my personal nature when I'm on a new website is that I always explore the purchase process prior to making a buying decision. I look for things like additional fees that are added at the end, how is my credit card processed, is it secure, what sort of information do they collect, etc. Normally in my exploration I go all the way to the end of the process before cancelling out and going back to continue shopping. It builds my overall confidence in the website and helps me decide if I trust it enough to give them my credit card. If I discovered my shopping cart contents was lost it when I pushed "Buy Now" it would seem a little strange and make me question the site.
If you create prompt when they push "Buy Now", I'd suggest making it an option that can be turned ON/OFF depending on the builder's preferences. For some people, this may not be a concern but I like the idea of telling clients they are leaving my gallery and the next steps must be done on the PayPal site. The wording could be something simple like "Your order is not complete until your payment is submitted through PayPal. Would you like to retain the shopping cart contents in case you abort the payment?" At least they'd know the gallery is handing the purchase off to a third party for completion and give them an option for retaining the shopping cart.
Thanks for considering this. It's not a huge issue but just a way to improve the professional appearance in a great skin. I appreciate your efforts.