Concept
Fogg Behavior Model (Motivation-Ability-Prompt)
behavior-design motivation product-design
Stanford researcher BJ Fogg's model holds that a behavior only occurs when three things converge at the same moment: sufficient motivation (how much someone wants to do it), sufficient ability (how easy it is to do), and an effective prompt (something that asks for the behavior right then). A shortfall in any one component, even with the other two strong, means the behavior doesn't happen — and critically, a low-motivation behavior can still occur if ability is made high enough, and vice versa.
The founding case: Instagram's pivot from a failed app. Instagram co-founder Kevin Systrom's original app, Bourbon, was a Foursquare-style check-in app that also let users post photos and earn points — cluttered with features, low on both motivation (few people wanted to share their location) and ability (the app was cumbersome). Systrom, a student at BJ Fogg's Stanford Persuasive Technology Lab, applied the model directly: he stripped Bourbon down to just photo sharing with easy filters (raising ability), leaned into humans' strong motivation for social approval by adding likes and comments (raising motivation), and built in prompts — both external (notifications when a friend likes or comments) and, most powerfully, intrinsic (an internal urge to share a moment — a holiday, a meal, a sunset — the instant it happens). The redesigned app, Instagram, was sold to Facebook for $1 billion within about a year of launch and later generated $55.8 billion in ad revenue in a single year (2018), reaching 2 billion monthly active users (see Instagram Bourbon Fogg Model Pivot Case).
A prompt is not the same as a message. Bas Wouters distinguishes the two with a billboard analogy: a highway billboard reading "McDonald's has lovely burgers," with no exit to act on, is a message — it doesn't ask for a behavior at a specific moment. The same billboard reading "take the next exit to visit our restaurant" is a prompt. Of the three model components, Wouters argues the prompt is the one marketers have the most direct control over — motivation and ability are harder to shift, but a well-designed prompt, delivered at the right moment, is comparatively easy to create.
Micro-behaviors. Applying the model to a business goal means breaking a single desired outcome down into its component steps and designing motivation, ability, and a prompt for each one separately. Downloading an e-book, for instance, actually requires five separate micro-behaviors: clicking an ad, reading a landing-page header, filling in a form, giving privacy consent, and pressing the download button — each one a separate point where the model can be applied. Instagram applied this at the level of a single "like": ability was raised by making liking a simple double-tap (no button to find), motivation was raised by showing that a friend had already liked your own photo (activating Reciprocity), and the prompt was social proof — seeing that other friends had liked a given photo.
Discussed in
- Episode 243 — 243-instagram-failed-until-it-made-this-simple-change