There is a concept called inflation. What it means is that the new tokens are created regularly. These tokens are distributed to the users who create value and contribute to the Steem eco system either by creation content, curating content, holding steempower or by being a witness. Quoting from the Steem blue paper
The rate that new tokens are generated was set to 9.5% per year starting in December 2016,
and decreases at a rate of 0.01% every 250,000 blocks, or about 0.5% per year. The inflation
will continue decreasing at this rate until it reaches 0.95%, after a period of approximately 20.5
years.
Of the supply of new tokens created by the Steem blockchain every year, 75% of those tokens
compose the “rewards pool” which are distributed to content creators and content curators.
15% are distributed to vested token holders, and 10% are distributed to Witnesses, the block
producers cooperating inside Steem’s DPoS consensus protocol.
Still does not justify my Potential Rewards... it was way too high and it should have been closer to $25 usd when I posed the question, not $700.