But selling software to others is usually to allow them to save money, they are lowering their ceiling and might approach the bottom some day. And then there is competition. When you have a lot of it it won&#x27;t be possible to charge any amount and someone might say that from now on you are going to focus on the low end of the market which means less focus on new advanced features. 
For internal systems it is usually very hard to stop using them after a while and there is also often a lot of things to develop in the systems. That means you are still contributing to the company. Stopping all development of internal systems might be very expensive.