You know when a space is hotting up when the start-ups move in, with strong VC backing from the same people who backed Paypal all those years ago.

Stripe, currently valued as a $20,000,000 company thanks to a $2 million funding round (from Sequoia capital, Andreesen Horowitz, SV Angels, Peter Thiel and Elon Musk). It’s also got the simple branding and name recognition that puts it squarely in competition with the likes of Square.

Beyond that, nobody is 100% sure. Unlike Jack Dorsey, the three man team behind Stripe are keeping everything close to their chest, but rather than go for physical card payments, Stripe appears to be aimed at monetising applications, providing developers with a simple API that allows payment services to be dropped into their code.

That would allow them to charge for in-app goods (for example $1 to have a magic wand complete a level of a puzzle game), but the key here is that Stripe simply enables this and takes their cut (5% and 30 cents), and they;re focusing on keeping that data available for developers – if they want to move on, then the credit card data (say for subscriptions) will be portable and accessible in a PCI-compatible format.

It might not mean much to a banker, but a coder is going to jump on that option. And that’s how I know the space is heating up. Smart people (developers) partnering with smart money (that’s an impressive investor list) to help more smart people (third party devs) make money. It’s like a circle of financial trust.