Achieving product / market fit is one of the most difficult things to do as an entrepreneur and the ultimate goal of phase one of the startup process. Most of this first phase of the process is spent building a minimum respectable product and doing whatever it takes to get the product into the hands of users — users provide the required oxygen for the product to improve. While most startups never make it past this phase due to funding, timing, lack of viable market, poor execution, etc., many do complete phase one and enter phase two where they have to build an efficient customer acquisition machine.

Here are five ways to identify that product / market fit has been achieved:

1. 10+ customers have signed on in a modest period of time (e.g. 3 – 9 months) and they haven’t been friendlies (people you already knew, favors you called…