[davedx]

It's certainly an involved and interesting service they're providing there, but it's still not a platform. You aren't writing software that runs on top of their software, you're connecting to their software with your own software. Those are two different things.

Windows is a platform.

Heroku is a platform.

Facebook is a platform (barely).

Android is a platform.

These are things you write software for that sits on top of their existing stack. Something providing webservices, no matter how many there are or how much business they generate, is not a platform.