What If An Agency Had An API?

Left this in the comments of Neil's post about the possibility of agency APIs: "The real data in a creative agency probably lies somewhere in 'ideas' (thoughts, sketches, designs, presentations). Starting to think about how an agency would build an API on top of that is very interesting (more for the agency itself than clients). But the problem there is one of structure: To build an API requires starting with structured data. The reality is that most of what agencies do is still mostly soft and not-so-easy to arrange." I then went on to talk about brand APIs a bit, which I still think is a really interesting concept but haven't put enough thought around to understand properly yet. Go read the whole thing and feel free to skip my comment.