When it comes to user rights, not every freelancer know much about them leave alone charging clients for the same. It's ok to use 'creative user rights' as a marketing tool when you are a newbie in the Freelance marketplace. I mean, you can get people buying from you if you are giving them 'rights' to use your work as a discount.
It's exciting when you hear how people start as freelancers then turn their experience into something beyond just freelancing- an online business enterprise. The beauty about the process is - you never know when it happens because you are having fun while at it.