I say this as a prelude to some stark data. It seems that in spite of the crash of "08" and the subsequent "Great Recession", job offerings in digital signage have quadrupled over the last four years. Further, there seems to have been o offerings prior to '06.
In truth, people have been using video displays as signage since there have been video displays. As I relate in a number of previous posts, the amount of "unaccounted" TVs, TVs sold in the US but not showing up in the sets per household numbers were always in the millions per year. Some of this was surveyed consumers loosing track of just how many TVs they owned, but most of the number were TVs converted to advertising or other commercial purposes. So the start of the employment numbers for "digital signage" was just the term coming into usage, not that there was no employment prior to '06.
The growth of the employment number in large part relates to the growth in the use of the term. However, much of that growth was probably expended by 2010 or 2011. At that time rather than the growth in employment offers flattening, it seems to have accelerated. Of course the offered graph charts job postings mentioning "digital signage" as a percent of all postings and some part of that growth would be do to a lack of jobs in other areas. But, even considering all of the other factors, that chart is fairly stunning.
this chart leads me to believe that employment in the industry is not only trending upwards but accelerating upwards.