• by Laurie Sullivan  @lauriesullivan, June 5, 2014

Marketers may be spending more on mobile paid-search campaigns, but the ad market will continue to fragment as the money moves. This year brands will spend $9.02 billion on mobile search campaigns -- climbing to $28.41 billion, or 85.9% of the U.S. digital search advertising market by 2018, per eMarketer. Apps will take more search dollars and share than some expect.

Newly released stats from the analysis firm show how search marketers continue to move money to mobile in an effort to meet consumers in a mobile ad market that eMarketer estimates will reach $17.73 billion this year.

Some 21% of U.S. consumers expect mobile devices to connect them with content on the Internet when they need it most, per a recent Forrester Research study that analyzes a shift in thinking about mobile connectivity. While younger generations are known to depend more on mobile devices, the survey of more than 8,000 U.S. online adults shows consumers age 65 and older are just beginning to warm up to mobile devices.

The biggest shift, eMarketer notes, indicates a change in consumer behavior that will cause google.com to lose market share to apps, which include Bing and Yahoo.

Google owned 82.8% of the $2.24 billion mobile search market in 2012, estimates eMarketer. While Google's mobile search revenue continues to increase, players in the "other" category continue to ramp up efforts to become the entry portal for mobile information. Companies that charge advertisers for listings like KAYAK, Amazon, Shazam and Yelp have begun to see profit, pre eMarketer.

Google dominates browser-based searches on mobile devices, but niche search apps have become more prevalent. This has caused Google's share to drop to 68.5% in 2013, as the long tail of other companies increased share from 5.4% to 22.9%, according to eMarketer estimates. This year, the analysis firm expects Google's share to fall to 65.7%, while the "other" category climbs to 27.3%.

eMarketer estimates that Yelp's mobile search revenue will grow 136.0% to $119.4 million this year, accounting for about 40% the company's overall search share. While the company only represents 1.3% of the search market this year, eMarketer expects Yelp's mobile search ad revenue to nearly triple by 2016 -- accounting for close to two-thirds of the company’s total search revenue, as well as for about 2% of the overall mobile search ad market.

As smartphone and tablet use continues to grow, it will become more important to define categories across the industry. Google and Bing lump search ads serving up on tablets in the laptop and PC category for bids, but allow marketers to segment tablets in reporting. eMarketer defines mobile search advertising as paid ads served by search engines, search applications and carrier portals to all mobile devices including smartphones and tablets.

eMarketer uses Google's run-rates to calculate its models. Enhanced Campaigns has an option of turning smartphone off, but tablet and desktop stay on all the time. They don’t have a breakdown of tablet vs. desktop. Since the model is based on actual numbers, eMarketer combines the data related to tablets with smartphones in forecasts.