Google's fourth-quarter earnings rose 17 percent despite the weakened online ad price during the holiday season. Google's consolidated revenue, which includes the Motorola smartphone business, rose to $16.86 billion from $14.42 billion in the fourth quarter of 2012.

Paid clicks on Google's online ads jumped 31 percent year-on-year, but the average cost per click that marketers paid Google declined 11 percent.

Revenue in Google's core Internet business totaled $15.7 billion in the last three months of the year, up 22 percent from the $12.91 billion in the year-ago period.

Google is trying to close the gap between the rates for ads shown on mobile devices and those on personal computers. As advertisers aren't as willing to pay as much for advertising across a mobile format, Google is offering them a single tool tweak their mobile and PC ad campaigns.