Cameron Gallacher

Always organize elements of information in categories no larger than 9, but preferably ~5 chunks.

…rs can be used to increase or decrease value by a constant amount and are great for making small adjustments (e.g. select the number of passengers).

To assess for product-market fit, look at retention. Do not look at the sheer number of people using your product or feature (which can be skewed by things like how aggressively you promote it.) Retention best correlates with whether your product is valuable because it tells you whether people who tried it liked it enough to return and use it again.