When you submit payment information to CIM, you get back different reference IDs to use when you want access to that profile or payment info in the future. If you submit the same information again, you get an exception back telling you it’s a duplicate… but if you haven’t written code to capture those IDs yet, or the code doesn’t work, you could end up with info stored but no way to retrieve or delete it since you don’t have the IDs.

If I wasn’t dumping all the output to the screen, I could’ve ended up permanently storing my own credit card with Authnet and having no way to retrieve or delete the associated payment ID. I’d never be able to buy from my own sites using CIM again since I wouldn’t have the payment ID and submitting it again would give me a duplicate info exception.