Me, a year ago, in how to rely on other businesses:
... if you're building something that depends on another business (or even entity), part of your business planning should be to ask yourself, what if they pull the plug tomorrow? Your answer may be "well, we'll find something else to do with our lives", but whatever it is, it shouldn't be "oh my god, I didn't see that coming."
Dave Winer, a couple of days ago, in Twitter is a corporate API:
Corporate APIs are good for the corporations that own them, and bad for everyone else. I would be reluctant to develop on any corporate API unless I was prepared to have my work completely deleted or obviated or usurped by the platform vendor. You really don't have any power. However it's impossible to avoid them. But try to. And don't be a crybaby when you get hurt.
We learn from History that people learn nothing from History. The same could be said of business and technology blogs!