• by Laurie Sullivan  @lauriesullivan, February 16, 2012

Nearly half of the travel industry's annual paid-search campaign impressions occur between May and August. With that in mind, investments in mobile, local sites and campaigns can create opportunities not only for companies, but consumers on the go.

Brands like Starwood Hotels & Resorts tap mobile to improve the experience, as well as capture last-minute hotel bookings.

Indeed, investments in mobile sites continue to increase. Since August 2011, Google has seen more than a 50% increase in the number of AdWords advertisers with a mobile optimized site.

Starwood gained success through click-to-call search campaigns on Google's network of sites using location-based extensions that allow consumers to tap into maps and directions. Working with digital marketing agency Razorfish, Starwood began running hyperlocal Google mobile search ads.

Michelle Ogle, digital marketing and affiliate strategy manager for Starwood, notes that the company's mobile search ad campaigns produced insight into the number and the duration of calls made by consumers to each hotel brand.

The search gave consumers easy access to map information and clickable phone numbers. That combination for Starwood produced more than 20-times the mobile paid-search ROI. Mobile bookings grew 20% sequentially, and the company also experienced a 200% increase in mobile traffic to its site, it said.

Google has seen mobile increase fivefold worldwide in the past two years, a rate comparable to the early days of desktop Google Search. Click-to-call ads from search and the Google Display Network generate on average 10 million calls per month. In December 2011, mobile search ad request volume rose more than twice as high as December 2010.

Matt Lawson, vice president of marketing at Marin Software, said search campaigns on smartphones and tablets accounted for 10% of all paid-search spend, up from 5% sequentially in Q4 2011.

More advanced advertisers build apps that allow users to connect directly through the app, rather than the site. "The challenge with apps, however, is that you lose visibility into performance," Lawson said. "Until marketers gain a way to track the online click from beginning to end, the app download and in-app engagement, the advertising spend will suffer from a lack of visibility. Investment will likely be suboptimal, as a result."

Companies supporting other businesses have begun to make investments too, making content more searchable, confirms ChainLink Research Founder Ann Grackin. These companies are adding social and multimedia features. She said collaboration, computing, enterprise apps, and consumer promotions are some of the driving factors.

Almost half of retailers plan to improve mobile Web sites by the end of 2012 -- and of those, 53% plan to optimize desktop sites for mobile use, while 44% plan to facilitate mobile transactions, according to Econsultancy, citing research from Stibo Systems. The biggest barrier, however, points to insufficient budgets, 58%, and legacy technology systems, at 37%.