I created an account on Coinbase.com, edited the Merchant profile and generated simple button code so that it should display a window and they'd manage the Bitcoin payment session.
I'm trying to add this to a Jade-rendered page.
//- Incoming params: title, user, message
a(class="coinbase-button", data-code="SANDBOXDATACODE", data-button-style="custom_large", data-custom="Order Sat 03 21 2015 - Sample UserName", href="https://sandbox.coinbase.com/checkouts/SANDBOXDATACODE") Pay With Bitcoin
The button renders correctly after a two-second delay. Pressing the button darkens the window content in preparation to then (hopefully) displaying the popup window content with their form. It just never diplays.