This chapter has been about licensing and intellectual property. Far too often, people spend so much time worrying about the code and the functionality of their application that they ignore the financial aspects of selling software. You won't make money if people can figure out how to use your software for free.
You need the ability to tell the difference between users of your product who have full legal right to use your product and those who do not. This can be done through various licensing schemes and different classes within the .NET Framework that enable class-level license control.
A combination of approaches such as obfuscation, licensing, and delegated back-ends supported by web services can provide an application that is very resilient to attacks and nearly impossible to pirate. This chapter has given you some insight into the concept of software licensing and you can produce a better, more sellable and secure product as a result.