Ask HN: What companies offer an API as a product?

Hundreds? There are even APIs for searching for APIs. http://apis.io/

For example we offer geocoding, which is a small website around an API for example. http://geocoder.opencagedata.com/

A bit meta, but companies use someone like Sheet Labs to offer API's as a product.

The API is never the product. It can be a huge part of the product, but it's never the product itself.

Are you looking at a particular use case?