The First Fourteen
The critical first fourteen days of product use, during which habit formation begins and the user decides whether the product is worth keeping.
The First Fourteen is the window in which users form their lasting impression of a product. It is long enough for the initial novelty to fade and the real experience to emerge, but short enough that users haven't fully committed. During the First Fourteen, users are evaluating: does this product make progress on my job? Is it easier than my current way? Do I feel competent using it? Products that deliver a visible win within the first fourteen days see dramatically higher retention. Products that require more than fourteen days to demonstrate value lose users to the status quo before the habit barrier is crossed.