The token STEEM is created out of thin air. Just like the USD and bitcoin. In fact any cryptocurrency or fiat money around the world is created arbitrarily. The real important question is instead: What gives the token any market value?
What gives any token, share or money value
When investors buy STEEM from the users in the system a price is set. But there is a more fundamental reason why investors would get STEEM in the first place. The short answer is an expectation of price gains because of the utility the whole system brings to market. Any token that wants to hold value long range has to offer utility to the users of the system long range and do this competitively on the market. If the utility of the system creates a demand for the token we can expect the price to grow as the user base grows.
What is the utility that steemit offers the market and in turn drive the demand for the token?
Art & content
The average content consumer that visit steemit is there for the art, articles and ideas. This is a value to his life. But this does not directly create a demand for the STEEM tokens of the system. They are attracted to be monetized.
Visibility, Attention & free speech
Attention or visibility is the main asset that creates a demand for STEEM tokens. If you want to be seen on the system you need upvotes and that requires STEEM power.
A cutting edge accounting system for storing and transacting value
Secondary is an advanced money system that users can use for commerce and a store of wealth. If integrated by payment processors this will in turn create a demand for the STEEM token and so increase the price.
Conclusion
The money comes from the monetization of the users by giving them great art and utility in the form of a superior banking system. Win-Win!