With Mobile World Congress just days away, Smart AdServer has published an infographic that reviews the three things you should learn from mobile advertising in 2011 – with a view to using them in 2012.

It shows that 50% of mobile traffic occurs after 5pm, and that CTR increases by 23 times the average if you use rich media ad units.

Among the operating systems, iOS on iPad gives the best CTR followed by iPhone and then Android devices.