Iron-Fist season 1 did not do well at all. Now the character did pick up when he was in The Defenders and his appearance in Luke Cage Season 2. But I think that shows that he does better when paired with other characters than when left alone.
Well in a few months, September 7th, Netflix will be releasing Iron Fist Season 2. Right now Netflix has been 50/50 with their Season 2 releases this year. Jessica Jones was not well received but Luke Cage ended on a buzz. It will be interesting to see if Season 2 will drum up excitement for the character of Danny Rand and continue the momentum of the Netflix Marvel series.