Stripe is rolling out a new way to do e-commerce on the on the web. Check out this tweet by @WarbyParker for an example. This is a huge UX win.
Today, mobile e-commerce websites aren't working: Ten-step shopping carts, mandatory account signup, slow page loads. When we get linked to a shopping cart on our phone, we usually just give up. That shouldn't be surprising—most mobile shopping sites are fundamentally the same as the desktop sites that preceded them, despite the medium calling for something completely different.