Hooked: How to Build Habit-Forming Products
This page should not be read as a study, because the source is not one. Hooked is a trade book for product managers and founders, published by Portfolio, in which Eyal sets out a four part model of habit forming products: a trigger, an action, a variable reward and an investment. It reports no experiment, no sample and no data of its own. What this publication cites it for is chapter five, on the investment phase, the one phase of the four that deliberately asks the user to do a small piece of work so that the product becomes more valuable to the person who did it, which is the commercial version of the claim the IKEA effect papers on this site test. The book was read in full in this vault and audited there, and the audit classes a model of this kind as a framework rather than as a finding, on the grounds that an argued model cannot pass or fail replication and should be cited as its author's way of thinking. So the evidence standing is that of a practitioner argument. Where the book retails a study, the study is the thing to cite, and several of them are on this site. There is also a book page for Hooked on this site, which is where a reader should be sent, and this study page and its near duplicate exist only because two articles cited the book through the study registry.
This page should not be read as a study, because the source is not one. Hooked is a trade book for product managers and founders, published by Portfolio, in which Eyal sets out a four part model of habit forming products: a trigger, an action, a variable reward and an investment. It reports no experiment, no sample and no data of its own. What this publication cites it for is chapter five, on the investment phase, the one phase of the four that deliberately asks the user to do a small piece of work so that the product becomes more valuable to the person who did it, which is the commercial version of the claim the IKEA effect papers on this site test. The book was read in full in this vault and audited there, and the audit classes a model of this kind as a framework rather than as a finding, on the grounds that an argued model cannot pass or fail replication and should be cited as its author's way of thinking. So the evidence standing is that of a practitioner argument. Where the book retails a study, the study is the thing to cite, and several of them are on this site. There is also a book page for Hooked on this site, which is where a reader should be sent, and this study page and its near duplicate exist only because two articles cited the book through the study registry.
Written from the book itself, read in full in this vault.
What our sources record
Reproduced as it was written when this source was checked, figures and all.
Portfolio. Ch. 5, Investment, pp. 135-162, the phase that deliberately asks for effort. Read in full in this vault, 2026-08-30.
Where we use it
- Why You Love the Thing You Assembled, Why We Come Back
Reliability of this reference
No persistent link has been resolved for this source yet.
The source
No link available. The citation as the article records it:
Eyal, N. (2014). Hooked: How to Build Habit-Forming Products. Portfolio. Ch. 5, Investment, pp. 135-162, the phase that deliberately asks for effort. Read in full in this vault, 2026-08-30.