For those who think their careers are washed up with age, take heart. Rapper Tupac Shakur may go on tour, and he's dead.

Although shot and killed 15 years ago, Shakur—or, rather, a hologram of him—appeared at the Coachella music festival in California recently. The technology is clever and slick. So is the promotional savvy.

But bringing a rapping ghost back to life offers an important lesson to entrepreneurs: Your intellectual property may have much longer legs than you think, and that might come back to, if not bite you in the rear, at least rub your nose in the dirt.

There are multiple types of IP in this example. At a minimum, there are property interests in Shakur's person, as owned by his estate, rights to the recorded performance, rights in the music itself, and various performance rights. If this holographic entertainment goes on tour, it could turn into a whole lot of very real money because of what all that IP makes possible.

Foreseeing your own posthumous reanimation might be asking a bit much from most people, but examples of losing IP to later regret are more common. I'm reminded of talking to a writer who was upset years ago. He had produced a large number of CD reviews for a website in exchange for the disks themselves. Short money for short amounts of content. He signed away all rights—and then found that the website eventually licensed all those reviews to Amazon.com. It was money he might have been able to make himself, except he had no concept of the ongoing value of what he did.

Most entrepreneurs don't realize just how much intellectual property they and their ventures generate. Get beyond the idea of a patent for a moment. Your marketing materials, product documentation, employee manuals, and many other things all have copyright attached to them. You might develop innovative business practices and insight, which would be know-how, and you might have trade secrets that give you a competitive advantage. Your brands, product designs, and service methods all have value.

That doesn't mean immediately rush to a lawyer. Some of your IP will need some sort of registered protection but much of it probably won't. Even so, you're better off thinking that everything you accomplish may have residual value. All too often, others have a better eye for the worth of what you do.

Before you give things away or write them off as worthless, consider how important what you have is to someone in your kind of business and what it would cost for others to create it from scratch. That is, if they actually could. The better a grasp you have on the true worth of yourself and what you've done, the better you can be in such areas as strategic planning and negotiation.