How do you know if you reached product market fit?

Product market fit, a term used by the startups ecosystem to identify if they have a product that satisfies a need for a number of customers for a problem they are currently facing. There is not a single unit of measurement if a startup reached product market fit or not. One of the ways to measure product market fit is if a startup is able to develop a repeatable sales process and are able to do basic forecasting for revenue. A product market fit is crucially important for the first product released by a startup but it’s also important for all upcoming releases of new products.