Traction is the rate at which a business captures monetizable value from its customers. It is the best measure of a working business model.
Note: monetizable value isn’t the same as revenue.
e.g. Facebook creates value for its users through its social network platform but it captures value (i.e. gets paid) from advertisers who buy attention and data. Users are a derivative asset and create monetizable value through their usage of the social network. Facebook can reliably use metrics like daily active usage (DAU) to predict future revenue from advertisers. These kinds of leading indicator traction metrics are more actionable than revenue.