One of my favorite startups, Square is doing some interesting work in a stodgy industry – with a viable business model from day one.

Fast Company took a look, but I love this idea of real-world A/B testing and the tools they’re rolling out to do that:

Square is providing an analytics system to vendors so they can track buying patterns and use the information to make adjustments that benefit their businesses. “How many cappuccinos did I sell, and how many of those customers bought biscotti?” Dorsey says by way of example. “So next week, if I move the biscotti jar, what happens to those sales?”