NEW YORK (TheStreet) -- Nielsen (NLSN - Get Report) may be down but it's not going anywhere.

Despite serving as a punching bag for media executives frustrated by mobile video, Nielsen is unlikely to be knocked from its perch as the industry standard for buying and selling advertising even as leading rivals Rentrak (RENT) and comScore (SCOR - Get Report)  plan to merge.

In a deal announced Tuesday, Rentrak and comScore said they plan to combine their companies in a transaction valued at about $827 million, merging the former's strength in television with the latter's specialty in digital. The combined companies have an equity value of about $2.4 billion, based on the share price at the close of trading on Tuesday.

Even as Nielsen is likely to remain the industry benchmark, the Rentrak-comScore merger promises to make the heated race for an accurate and accepted means to measure mobile viewing much more interesting.

"We believe the industry is looking for a better/best measurement solution to its audience crisis," said Bernstein Research media analyst Todd Juenger in an investor note on Comcast. "We don't believe the industry will find that from comScore/Rentrak -- not even close."

Nielsen's strength remains its size and reach, Juenger said. Unlike Rentrak and comScore, Nielsen tracks media viewing nationally and also by individuals rather than devices. Importantly for its TV network clients, Nielsen is able to report overnight viewing numbers for most programming. Rentrak's television data is largely from set-top boxes.

To be sure, Rentrak and comScore are likely to put more pressure on Nielsen.

The two companies have been working together for more than two years on an effort called Project Blueprint, which seeks to combine data from the two companies -- Rentrak's TV with comScore's digital -- along with Nielsen's own People's Meter. The project, led by comScore, secured the participation of ESPN, ABC, CBS, Fox, NBC and others, all of which are closely watching to see whether it can become a genuine alternative to Nielsen. 

"The deal addresses an imperative need for a flexible and trusted metric for cross-platform media buying and selling, with siloed TV and digital analytics no longer adequate," Matthew Harrigan, a media analyst at Wunderlich Securities, wrote in an investor note.

And an alternative, or at least a set of comparative data, is what the industry has said it wants.

"We are woefully behind in virtually every kind of measurement and nowhere near where we need to be in cross-platform measurement," Alan Wurtzel, president of research and media development at NBCU, a unit of Comcast's (CMCSA - Get Report) NBCUniversal, told AdWeek back in March 2013.

Viacom (VIAB - Get Report) CEO Phillippe Dauman has been among the most vocal, in part because the viewers of his chief networks, MTV and Nickelodeon, are mostly young people who are most apt to be accessing its programming over mobile devices rather than a standard television. Dauman has often complained that Nielsen has too-often failed or been slow to track viewing on mobile devices such as Roku as well as smart phones and tablets.

"Inadequate measurement undermines innovation and disproportionately impacts those leading programmers like us who effectively provide the multiplatform experiences that viewers demand," he said during a spring earnings call.

That Nielsen's People Meter is the largest source of data providing the most extensive demographic breakdowns is widely accepted even by Rentrak and comScore. The two companies simply proclaim that they can do a better job of tracking usage on smartphones, tablets and devices such as Roku and Tivo. 

The merged company will also be open to criticism about its impartiality given that the world's largest marketing company, WPP Group (WPPGY) , which purchased a stake in comScore in February, will own 16% of the combined company with an option to increase that position to 19.9%. WPP, headed by Sir Martin Sorrell, owns the advertising agencies J. Walter Thompson, Ogilvy & Mather, Young & Rubicam and Grey, among many others.

But whichever company reigns supreme among advertising buyers and sellers, the underlying issue of viewers' transition to mobile devices, away from pay-TV services, will continue to force media companies to adapt or perish.

"We believe a lot of the industry trash talk was simply using Nielsen as a convenient scapegoat while the TV networks figured out a strategy for dealing with their real problems," Juenger added.