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.”

needs contextconfidence: 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.

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