I recently got a question about configuration vs customization. In The Membership Economy, I point out that ownership is about customization, but membership is about configuration.
In software, customization requires professional services to do, and can't be "reset" but the sky's the limit. Configuration means the product has been designed to be used in different ways by different people, but those options have been built into the product and the options are limited. The advantage to configuration is that it's much easier to reset and/or maintain, since that's how the product was designed to be used. For example, I have a special way I like to configure the driver's seat in my car. I like it high, and forward, with the headrest tilted. An engineer I know has replaced part of his car's seat with a seat from a different car. I configured. He customized.
Customization is not scalable.