Money now is better than money later. If you have a secret that is guaranteed to make money, but only over the course of several years, you could just sell it now and get that profit today instead of waiting.

The person buying the secret will pay less than the long term profit as a fee for them giving you the money upfront now.

But if you have rights to resell the secret multiple times you will earn money far quicker, perhaps more than the secret’s long term value.