Although I'm now getting paid a good salary, there were several years where it was insufficient and I felt very underpaid. After writing the CEO, he said it would be taken care of, but nothing seemed to change for months. So I decided to leave. I gave multi-month advance notice so I could train a replacement. Then they took action, significantly upping my salary and asking what I wanted, offering a new title etc. After 3 consecutive large annual salary bumps, my salary had been reset about 60% higher than when I was ready to leave.