You should consider selling or merging your company when it doesn’t feel like yours anymore, when it feels like something that’s attached to you but no longer is you. If you’re a founder of a company, you have a completely weird relationship with your business. You and your business are intertwined.
At some point your business becomes a lot bigger than you. While you’re important to it, you’re not irreplaceable. If you no longer feel like you can serve the organization in a way that provides unparalleled benefit, then it’s probably the time for you to think about merging or selling because it will allow you to find a place where you can add all the value that you’re capable of.
It’s the building that excites most founders, not the management. If you’re enthralled with being an executive, that’s awesome because you can stay with the company for a long time. Ultimately, the time to sell or merge is about you, when you’re tired of investing yourself into it or when no matter what you invest, the business needs something else. If your business isn’t healthy, it may be time to shut it down.