Comment by couradical

There's no requirement to go "public" in the sense of listing on an exchange, and available for public purchase. What changes at that point is SEC regulatory compliance kicks in: earnings/revenue go public, SEC compliance paperwork has to be filed just like a public corp. That's really why people try to stay under that number - you have all the drawbacks of being public, except a floated share price, and it would effective crush any IPO pop that they would expect to get, as financials would be totally available, so offer price would have to reflect the company's financials.