Along with the growth of APIs in general has come the emergence of the API as a product. Many times a new startup is entirely an API. When the entire company is an API, you'd better choose the right API business model. When the API is the product, or the whole business, many times this means charging developers to use your API. It turns out, it's not just about how much you charge them, but how. This post will look at the many different ways that API-as-product companies are getting developers to pay for access.