A customer doesn't have to pay for a service in a direct manner. We actual create (partially) a value for Steem and Steemit UI, we pay with our time spend, with our knowledge we share in the community; With our activities/projects we define and execute using the Steem blockchain and services around it.

Using your explanation, anybody who offers service without a direct payment involved from the user (the customers and consumer) towards the service owner (the supplier) does not have any obligations. Facebook therefore does not have any obligations to its users? Skype doesn't have any obligations to its users? WhatsApp doesn't have any obligations to its users? WeChat doesn't have any obligations to its users? Whole businesses are build around these free services. These service owners are earning a lot of money because of all these free users. With the third industrial revolution, producers and consumers, suppliers and customers definitions and models changed.