Spending on mobile search in the US increased 333% in Q2 2012 compared to the same period last year, according to a report from IgnitionOne.
Impressions are also up 130% year-on-year (YoY), and clicks increased 325%.
Overall, mobile search made up 14% of total search advertising spend in Q2, up slightly from 12.3% in Q1.
This is similar to Q1 stats reported by Adobe, which found that mobile now accounts for 8% of US search spend compared to 11% in the UK.
IgnitionOne's report shows that of the overall mobile search spend, tablets account for 60% with smartphones making up the remaining 40%.
This is also comparable to Adobe's stats which found that tablets accounted for 4.25% of the combined total of 8% for mobile search in Q1.
But despite the rapid increase in mobile search, we have found that brands are failing to take advantage of the opportunity.
Looking at the PPC results for the top three search terms in the UK, only six out of the 15 paid search results linked to mobile sites.
This is a huge missed opportunity for these brands, and means some of the money they have spent on securing prominent positions in paid search is potentially going to waste as they have failed to account for the mobile searcher.
While mobile search spend continues to experience massive growth, paid search spending grew at 15.5% YoY, representing a slowdown compared to the increasing growth in the past two quarters (22.4% in Q4 2011 and 30.3% in Q1 2012).
The YoY increase in clicks also slowed compared to the previous quarter, up 13.2% compared to 29.1% in Q1. CTRs were flat YoY but impressions grew faster than last quarter, up 13.7% YoY compared to 7.2% in Q1.
Looking at CPCs, in total they were up 2.1% YoY, however Google's CPCs continued to decline (down 3.1%).
This continued decrease can be blamed on increasing reliance on mobile, which has cheaper CPCs as well as increasing use of new ad formats which are generally lower PPC clicks.
In contrast, Yahoo and Bing's Search Alliance saw CPCs increase by 24.3%.
IgnitionOne attributes this to promoted best practices that have led to greater competition in auctions "through the increased use of broad match keywords as a stepping-stone for exposure across other match types".