The problem for google is three fold:
1. Mobile ads pull in a fraction per click of what Desktop ads do
2. Mobile advertisers aren't stuck with google, they are flocking to social network ad placements such as Facebook, Google will never have the same dominance on mobile that they did on the Desktop
3. Goldman Sachs just estimated that 75% of Google's mobile search revenue comes from iOS...while it's very clear that Apple is setting up it's future iOS versions to cut out Google (Siri enhancements, Apple Search, etc.)
So yes, mobile is helping Google, but even if they got 100% of mobile ad serve revenues, the cost per click is a fraction of Desktop search. It's like replacing the V8 in a pickup with a 4 cylinder engine. It'll still do *something* but it will never be the same.
http://www.nytimes.com/2015/05/28/t...or-android-despite-market-dominance.html?_r=0