There are plenty of dual licensed codebases that make a profit with no additional value add (other than not having to respect the GPL.) For example, the popular

There are plenty of dual licensed codebases that make a profit with no additional value add (other than not having to respect the GPL.) For example, the popular C++ gui framework JUICE[1] [1] http://www.juce.com/faq#t78n75645 http://www.juce.com/faq#t78n75645