Taking people's money on the internet is a HUGE pain. The only other potentially "easy to use" alternative would be Amazon I believe https://payments.amazon.com
Most everything else is going to require a merchant account.
Our experience is that amazon's payment approval process is long and strict for the consumers who have credit cards that are not from the major banks. About 5-8% of our payments ended up rejected by Amazon, while the customers contacted us and told us that they use that credit everywhere and on paypal fine. Some of them have to send us a check, but most of cases, we just lost the customers. We are switching to paypal.
I'd be interested to know what the Amazon response was to this support request.
Surely, if Amazon Payments can't process it then Amazon stores can't be purchase from with these cards either and some not insignificant value of purchases are failing at Amazon's card verification stage?
Their revenue is according to WolframAlpha approaching $30Billion .. 1% of 5% of $30B is $15M USD.
It's not that much harder to do than PayPal (took me about two weeks), and keeps you from having your customer's credit card info locked into some third party service that you can't get out of.
http://www.2checkout.com/community/
Also, google payments may work for you.