The Lean Startup: How Today's Entrepreneurs Use Continuous Innovation to Create Radically Successful Businesses · chapter 10 · id the-lean-startup-c10-01-there-are-three-engines-of-gro
“There are three engines of growth: sticky (retention-driven), viral (word-of-mouth coefficient), and paid (customer acquisition cost vs. lifetime value). Every startup relies on one primary engine.”
TRUE, BUTconfidence: high⚠ extracted by pipeline, re-audit pending
Receipts
Dave McClure, Startup Metrics for Pirates (AARRR), 2007source alive
McClure's AARRR framework (Acquisition, Activation, Retention, Referral, Revenue) covers all three of Ries' engines and more, published 4 years earlier.
Andrew Chen, viral growth and growth frameworkssource alive
Viral coefficient, CAC/LTV analysis, and retention curves were well-established growth concepts in the startup analytics community before 2011.
This claim is a stable, citable object. If you can falsify a verdict, tell us. Corrections are loud here.