NEW YORK (The Deal) -- The pending combination of ComScore(SCOR) - Get Report and Rentrak (RENT) will intensify the competition with Nielsen(NLSN) - Get Report to establish a definitive gauge for measuring digital media and advertising.  

The media measurement companies announced a merger Tuesday under which Rentrak shareholders would receive 1.15 ComScore shares for each of their shares. The deal had a value of about $730 million as of Tuesday's close and more than $800 million by Wednesday.

"We've built these two companies individually to really be brought together at some point," Rentrak Vice Chairman and CEO Bill Livek said in an investor call late on Tuesday. Livek will be executive vice chairman and president of the post-merger company. ComScore, of Reston, Va., has focused more on the digital media world, while Rentrak has tuned into television. 

It's hardly the first time ComScore, Rentrak and Nielsen have used M&A to gain a new foothold in the digital advertising landscape.

ComScore CEO Serge Matta, who will keep that role at the post-merger company, said the main forces of change are the movement of consumers across devices, the ubiquity of video and television and the increased automation of the advertising market. Keeping tabs on the three factors have driven the company's M&A strategy.

Back in 2008, ComScore homed in on consumers' use of wireless devices by purchasing M:Metrics, a company that measured mobile traffic by monitoring behavior of user panels. 

The company purchased AdXpose, which tracks advertising traffic and data captured through digital advertising campaigns, in 2011. Last year, ComScore purchased MdotLabs, which attempts to ferret out fraudulent digital traffic and bots that can distort the information that companies use to buy advertising.

Rentrak also has used M&A to broaden its offerings. In 2013, the Portland, Ore., company acquired iTVX, which tracks and analyzes data about major brands across TV, movies, Internet and social media.

Last year, the company bought a television data analytics business from the Kantar unit of London advertising and media group WPP (WPPGY) . Rentrak also negotiated a deal to integrate its national and local TV measurement with WPP units.

WPP CEO Martin Sorrellhas been an outspoken critic of the current state of data available to advertisers. The company holds stakes in both Rentrak and ComScore and would hold 16% of the post-merger company.

If Sorrell liked what he saw from the combined company, WPP would have the option to buy up to 19.9% of shares. WPP would not have a seat on the board, though, which would include eight directors from ComScore and four from Rentrak.

Meanwhile, Nielsen also has used M&A to up its game. In March it purchased technology group eXelate, which allowed the company to pump its media metrics into advertising buying and selling platforms developed by other companies.

Matta told investors on Tuesday the demand for media metrics that can cross devices and distribution platforms is urgent.

"The industry is begging, it's pleading for it," he said.

ComScore and Rentrak aim to close their merger by early 2016.

--David Marcus contributed to this report.