Moving to other countries will take time as each country has their own banking/financial/etc issues that need to be dealt with.
It took years for PayPal's Web Payments Pro to go from US only to US, UK. And then a few more years to go to US, UK and Canada.
Amazon FPS has been around for ages and is still US only.
So it may be a while.
The fees for Stripe are 5% + $0.30.
However when you take a deeper look you see that things are not so simple.
Compared to PayPal's free product, you are not forced to leave your website and go to a 3rd party site to complete the transaction.
Compared to PayPal's Web Payments Pro product, you don't have the $30 monthly fee.
Also this doesn't even taken into consideration the complexity and cost of implementing PayPal's Payments Pro api vs Stripe's simpler JSON api.
I understand this is a usability win, but doesn't this subject the original web app to PCI compliance rules?
If the form that the user puts their credit card info into POSTs to your web server, then you are on the hook. Now that I think about it, the form may POST to a third party payment processing web service from your web app which prevents the user from feeling like they have left your web app. In that case, I think that your web app is off the hook for PCI compliance.
Just from a subjective perspective based on the history PayPal has had with withholding funds etc...
How does WePay compare to Stripe?
JSON-based HTTP API
Setup in 5 minutes.
No branding requirements or redirects.
5% + $0.30 per transaction.
US Based Sellers Only.
Recurring Billing Support.
Data Portability if you ever want to leave.
You pay all initial fees (5% + $0.30) if you issue a refund.
You will only receive money at the end of the next month.
WS callbacks (aka webhooks) that notify you before a recurring payment happens, and after success/failure.
Incremental billing support, so you can e.g. tack on overage charges or small micro-charges to the next upcoming bill without needing a separate transaction for each one. Depending on your business model this could save you a lot of transaction fees.
What will be more interesting is if they can match both Amazon and PayPal's microtransaction rate of 5% + $0.05 for products under $10 (Amazon) to $12 (PayPal).
Stripe is quite literally double Braintree's rates, with no value-add.
And on top of that, they hold the float for up to thirty days?
Good luck, guys. You're going to need it.
'Cause that's what I've seen so far from Stripe. They're incredibly responsive and helpful. They even changed their SSL cert provider for me because older BlackBerries had a rough time with their prior cert provider.
Not to rag on Braintree, they've sounded like a good choice for a long time, but Stripe's changing some of the rules of the game. Killing the need for a merchant account is a really big deal and I'm happy to pay their rate.
 This isn't a rhetorical question, actually. I'd be interested in whether you can do this with Braintree.
All designed and written in the last few years, and thus completely free of legacy insanity from the 70s.
You need your own Merchant Account though. They'll find you a provider if you need one.
But I can speak to the economics of all this "complexity" of which you speak.
We currently use CyberSource for our gateway and associated banks for our Merchant Accounts, and we maintain several accounts. Each account takes less than a day to set up, with our representatives at each company.
Integrating with the CyberSource API takes roughly 20 developer-hours.
An increase in transaction costs to 5%+0.30, would cost us roughly the salary+benefits+taxes+overhead of two fulltime developers, per year. That's a cost that's simply unacceptable.
There is also the issue of "killing the need for a merchant account", being problematic from a number of legal/accounting angles( tracing this transaction from A to M, entity separation and identifcation ), as well as customer service angles( what is this PAYCSTRIPE_TCMERCH charge on my card?? ).
There is no way that any merchant account provider would allow you to sign up and start charging customers in 5 minutes like Stripe lets you.
About time a YC quality company gets in that space.