The big money in open source lies in making it special. (A 16x20 matted print of this special scene is $30 from the Norman Rockwell Museum in Vermont.)
This is why open source does much better, financially, in the enterprise space than anywhere else.
Every enterprise is special. Every enterprise is looking for an edge, and will pay to attain or maintain that edge.
An enterprise computer system is your offense in the business wars. Getting it to do what others can't gives you an advantage. Managers are forever seeking that advantage.
So the fact your software can be seen, or changed by your customer, does not keep you from profit. By making it special, through add-ons and services, you can deliver value and get paid.
The problem for mass market open source is this model doesn't pay. Mass market software, by its nature, must be usable by the masses. What you need for mass market acceptance seems to have no relation to what you need to make money.
The answer is to change your idea of who the customer is. It's not the ordinary user. It's the service which is enabled by the software which is your customer.
That's the heart of Google's open source strategy. The company is trying to make its services the heart of mass market open source software. It has a business model for those services.
Let me suggest this is the way to look at your own profit in this area. Are there services you can make essential to people by adding-on to popular open source products?
Of course there are, and if you can deliver these advantages to services with a business model you can get paid for it.
Just remember today's special Thanksgiving clue. To make money, make it special.