> A startup is a company that hasn't identified a profitable business model.That seems like an equally useless definition. The profitability of many business models, especially ones in tech and manufacturing, is dependent on their scale so there's a circular dependency. More importantly, the meaning of "identifying a profitable business" is itself unclear. If I open up a new coffee shop in town, is my business model selling beverages, selling coffee, or selling coffee to the ~20k people who walk through my main street location (I'm using a small business example for simplicity's sake)?
That's why I often hear the term "product-market fit" as a way to describe startups. A coffee shop's market is set based on location and the product is a combination of the coffee and atmosphere but the area might be too competitive or too low volume to be profitable. In my opinion, even a coffee shop can be considered a startup until it is in the black and a small business afterwards because there is little opportunity to grow.
> Legally, the definition is further restricted to a company which hasn't begun revenue-generating activities.
This is better but then what is "revenue generating" activities? Putting up a Stripe form? Sending out sales people? Doing some marketing? Several of my previous startups had early stage partnerships which paid out a decent amount of money in exploratory contracts before we pivoted to the final iteration of the product. We may have even been profitable for a short while but I'd find it hard to argue that we weren't a startup or that we were a small business/established corporation.