Although mobile represents less than a fourth of paid search clicks, smartphone and tablet search clicks have grown 89 percent year-over-year, according to a new study from The Search Agency.

The Search Agency?s ?State of Paid Search Report? from the fourth quarter of 2012 looks at search trends on engines, devices and industries. With the addition of new tablets and smartphones in the market in the past year, the report points to a growing competition in mobile search this year for marketers.

?Advertisers can no longer ignore the experience for smartphone and tablet,? said Keith Wilson, vice president of agency products at The Search Agency, Los Angeles.

?Mobile strategy must incorporate the user intent, the platform used and develop unique content and on-site experiences designed to align the audience?s intent to content,? he said.

Search on mobile
When it comes to advertising spend, the report shows that marketers are increasingly investing in smartphone and tablet search.

According to The Search Agency, advertising spend on mobile increased every quarter during 2012. In the fourth quarter of 2012, mobile represented 15.6 percent of spend. This is a 79 percent year-over-year increase.

Additionally, tablets are an area of high growth for marketers. In fact, the report found that the fourth quarter was the first time that spend on tablets exceeded the spend on smartphone mobile search.

Tablets made up 8.5 percent of the mobile ad spend, and smartphones made up 7.1 percent.

Over the past year, there have been numerous new tablet devices that are all vying for a piece of the space. The report credits the number of new devices as the reason why tablet click share has more than doubled year-over-year.

Take Google, for example. For the first time, tablet impression share on Google exceeded smartphone impressions due to the increase in tablets including Amazon?s Kindle Fire and the Google Nexus 7.

PC search made up 84.7 percent of impressions with tablets generating 8.4 percent and smartphones bringing in 6.9 percent.

Additionally, Bing saw an uptick in mobile device impressions and click shares but still only represents a small amount of impressions and share compared to Google.

For example, Google reigns over 88.8 percent of both tablet and smartphone spend. Bing controls the remaining 11.2 percent.

Per the report, tablet impressions generated 2.8 percent of impressions, which is barely below its 2.9 percent of impressions in the third quarter of 2012. Smartphones brought in 3.9 percent of impressions, representing an increase from 3.4 percent in the third quarter of 2012.

As the competition heats up in mobile search, overall cost-per-clicks increased seven percent while click-through-rates decreased seven percent.

The average cost-per-click for desktop was 64 cents. The average smartphone cost-per-click was 30 cents and tablets came out to 50 cents.

Overall impact
Overall, spend on search advertising grew 11 percent year-over-year, according to the report, fueled by mobile search. Smartphone spend increased 44 percent and tablet spend grew by a whopping 199 percent year-over-year. Desktop spend on the other hand only increased three percent.

Despite the growth in mobile search, Google and Bing continue to claim the same portion of desktop spend, per the report. Smartphone share of spend increased 58 percent year-over-year, representing 11.2 percent of total ad spend. Similarly, tablet share of spend grew 42 percent, which also equates to 11.2 percent of total ad spend.

Total impressions also increased 11 percent and total clicks rose four percent, according to The Search Agency?s findings.

With holiday shopping in full swing, the retail industry saw a 20 percent quarter-over-quarter increase in click traffic. Retail click volume was down six percent year-over-year.

?Most notably, impression share on Google for tablets was greater than impression share for smartphones for the first time ? an indication that consumers and advertisers embrace the tablet platform,? Mr. Wilson said.

?Tablet share of click traffic and spend will continue to outpace smartphone growth,? he said. ?Smart advertisers will prioritize a smartphone strategy that aligns with understanding the intent of the audience and align unique metrics indicative of revenue generating activities and optimize using those micro-conversion data points.?

Final Take
Lauren Johnson is associate reporter on Mobile Marketer, New York