Platforms and aggregators both enable new kinds of experiences in their ecosystem that wouldn't be possible without them.

Platforms support from the bottom, lifting up possibilities.

Aggregators support from the top (cornered consumer demand), lifting up possibilities.

But aggregators fundamentally set a ceiling: "As a participant in my ecosystem you can do anything up to this level, but no higher."

A true platform doesn't set a ceiling of possibility on its ecosystem.

An aggregator, like a platform, creates the opportunity for an adjacent ecosystem.

But unlike a platform, an aggregator is closed.

As is often the case, Gordon said this better two years ago.