We're all sure they have big margins in their raw API, it's the subscription we're claiming is subsidised.

Oh I know. But people often point to the API usage cost as an indicator of the magnitude of subsidisation, or to say that the big labs are far less efficient than cheap competitors.

I'm saying that this is not necessarily the case. They do a lot of optimisation and don't have the same price pressure to lower margins. They may not be losing as much on subscriptions as people think.