This is data from one client:
Here is data from another:
And here’s another:
Two important things here. The first is the range. 15% to 80% of traffic comes from mobile. This depends far less on global trends than upon the nature of your community. If it’s a community people visit to get answers while doing work, expect it to be low. If it’s a community people visit to see what’s new, what others are doing etc…expect it to be much higher.
The second point is it’s stalling in many of our clients right now. It might fluctuate, but we’re seeing (at least in markets with high mobile penetration), the percentage of visits by mobile has likely peaked.
This means you should allocate your resources (time, energy, money) by where people visit today instead of extrapolating from past trends. i.e. if 85% of your visits land at a desktop version of your site – spend 85% of your resources there (and vice-versa).
Aside: we generally see desktop traffic to be much more valuable. People tend to browse on mobile but make their best contributions when sitting at a laptop.