House hunting services have gone mobile, creating a land grab for companies that specialize in the space. Against the backdrop of a recovering real estate market since the recession, more people are downloading applications that streamline the often stressful and daunting task of finding a home to buy or rent. As a result, companies such as Walk Score, Trulia, ZipRealty and Move Inc. have been actively pursued as M&A targets.

Like other corporations that have treated 2014 as the year to start buying, Seattle-based Redfin finally embraced M&A this year after spending years growing organically. In October, it picked up Walk Score. With just 10 employees, Walk Score puts Redfin in direct competition with larger, more acquisitive rivals.

According to Redfin CEO Glenn Kelman, the company had been looking to give users a "portrait of what it would be like to live somewhere new."

Walk Score, also based in Seattle, provides tools to measure "neighborhood walkability services" by calculating the distance from specific addresses to neighborhood amenities, such as restaurants and libraries.

Walk Score, founded in 2007, will provide real estate agents with more efficient information,

The deal comes on the heels of Redfin rival Zillow's (Nasdaq: Z) acquiring San Francisco-based Trulia for $3.5 billion in July. The deal positioned a unified Zillow and Trulia to capture a larger share of digital real estate ads, as well as enable property agents deploy more marketing dollars on the Internet. Redfin is expanding, but Zillow and Trulia are the top two most-visited property sites in the U.S. tracked by ComScore Inc. There was also the $165 million acquisition of ZipRealty Inc. by Realogy Holdings Corp. in August, as well as News Corp. (Nasdaq: NWSA) buying Move Inc. for $899.2 million in early October. That deal came after Move Inc. inked a deal of its own, buying assets from Yardi Canada Ltd.'s Point2.

"Digital real estate is an important pillar of our global digital strategy," News Corp. chief Robert Thomson told analysts recently. "There is a massive market in the U.S. for online real estate revenue and we believe this market is in its early stage of development."

Buying assets in the digital real estate sector also offers opportunities for companies like News Corp. to reclaim territory lost as print classified ads migrate to the Web. The Rupert Murdoch -led company also owns a 61.6 percent stake in REA Group Ltd., which operates an Australian residential-property website.

Agents and brokers spend more than $10 billion each year to market homes. As traditional forms of advertising, via newspapers and direct mail, begin to fade - that small fraction of money spent online is expected to grow. As a result, buyers see the space is ripe for consolidation.

Companies that have yet to be scooped up include Market Leader (Nasdaq: LEDR) and LoopNet.