If you have an American Express or Discover card, you can still make purchases on Leanpub -- just not using our credit card form!
The way you do this is using your credit card on the PayPal website. You do not need to create a PayPal account to do this.
Here's how it works:
Go to the Leanpub checkout.
Choose PayPal on our form.
Choose your country.
Click "Purchase with PayPal".
On the PayPal site, click the grey "Pay with Credit Card or Visa Debit" button.
Enter your credit card information.
We're sorry that this is a bit of a hassle! We're Canadian, and PayPal Website Payments Pro doesn't work quite as well for Canadian merchants as it does for US merchants...