By The Time You Give Them a Raise, They’re Already Out The Door
On the other hand, if you're an employee and not getting paid what you think you're worth, don't jump to the conclusion that you're being exploited or disrespected, and don't jump to the conclusion that you have to leave in order to get market rate.  If you're happy with the team and with the work, consider just asking for what you want.  Founders are crazy busy and, believe it or not, sometimes lose sight of "little" things like comp.  Talking to them may be all it takes.