- p drives early adoption and q drives word of mouth.
- A higher q brings a steeper S-curve.
- Fit the rates to early sales data.
What the two rates mean
The innovation rate p is the share of the remaining market that adopts in a period without influence. The imitation rate q is the extra push from contact with earlier adopters. Typical values for consumer durables are p near 0.03 and q near 0.38.
Reading the curve
With a market of 100,000, p = 0.03 and q = 0.38, about 43,900 people adopt within six periods and about 90,900 within twelve. Sales peak in period 6.2, then decline as the market fills.
Use it in planning
Plan stock, support and ad spend around the peak. To move the peak earlier, raise q through referrals and social proof, or raise p through broader awareness.
How fast will a launch reach its market?
Questions about Growth Loops and Referrals
Can I use it for software?
Yes, with a defined addressable market and realistic rates from comparable products.
How much data do I need to fit p and q?
Eight or more periods of sales give a rough fit. Earlier forecasts rely on analogies.
Key terms
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