I just came from reading the NewZoo 2016 global game market report. The last time I read it, I noticed that the web game's segment was less than the years before (it was 5% in 2016, 6% in 2015, 9% in 2014, and 10% in 2013)
But these are all for users who accessed games using their PCs not mobile phones. And if you've been following the current trends of game portal websites, you'll notice that they are moving to mobile. Both Kongregate and Miniclip, two very big gaming portals, have started publishing games on the two major app stores. They (and the larger part of web game publishers) will usually reject any HTML game doesn't support mobile. So they are definitely aware of this trend.
So now my questions is: what are the stats when it comes to web games on mobile? Does anyone know any resource that has stats on this?