title_body: Porter in the Marketplace
upvoted_answer: TL;DR: Yes, but they're growing.
  
  
  
  This chart shows, for craft beer sold in 2012, the relative portion of the market each style made up, with IPA being the most popular (a relatively new occurrence).  Porters do not even show up.
  
  
  
  Here's another for 2011 showing porters as quite low on the list.
  
  
  
  This chart shows the year-over-year increase in sales by style.  You'll note here that, at least in 2011, porters weren't growing very fast either.
  
  More recent data was a little hard to come by, but it seems that the overall sales numbers are unlikely to change that much in a couple years: IPAs, Pale ales, Ambers and Amber Lagers are probably still topping the charts.  So it's not that porters don't sell at all, but they're certainly not top earners.
  
  Drifting into conjecture, I would say that the people interested in 'big beers' will take a stout over a porter, and those interested in a more subtle beer will go for a brown or an amber, leaving porters in a bit of a no-man's-land in the middle.