… the most important distinction between platforms and aggregators: platforms are powerful because they facilitate a relationship between 3rd-party suppliers and end users; aggregators, on the other hand, intermediate and control it.
— Ben Thompson, in ‘The Bill Gates Line‘
And the original:
A platform is when the economic value of everybody that uses it, exceeds the value of the company that creates it. Then it’s a platform.
—Bill Gates, as recounted by Chamath Palihapitiya