An acquisition metric measures developers’ initial sign-up or adoption of an API. It belongs to the API product metric categories used to track action metrics and leading indicators for management’s focus metrics. section 11.1.3
Interpret the developer as the primary API user: API calls from an integrated application and its associated API key count as coming from that developer, regardless of the application’s end-user count. Developer account sign-ups by referral channel are identified as a related measurement example under discovery metrics. section 11.1.3
Figure 11.5 Extending the developer journey map with API product metric categories
Use the developer journey map to place acquisition alongside discovery, engagement, activation, retention, and experience metrics. section 11.1.3

