[MiguelHudnandez]

> by the time I'm entering my credit card details, I'm already "converted".

No, when you finish entering your credit card information, you're "converted."

I have been ready to purchase but abandoned orders because I was doing multiple things. By the time I remembered to go back, I didn't feel as strong a compulsion to purchase the product. In some of these cases, if checking out were easier, I would've been done and I wouldn't have felt strongly enough to cancel the order.

Shitty forms cost you money even when it's the last form you have your users fill out.