Essence suddenly drew the spotlight earlier this summer when WPP's GroupM said it would invest more heavily in the digital agency, which it bought in 2015, partly through merging two other agencies with bigger names.

Now, Essence is gaining two major clients from elsewhere in GroupM, Target and NBC Universal, which will more than double its media billings to nearly $3 billion.

GroupM, the largest media buyer in the world, is tasking Essence, historically a purely digital agency known for handling Google's digital media, with figuring out how to better measure traditional media using data and insights. That's a challenge that many in the industry are racing to tackle. The agency intends work with its clients to build new capabilities in these areas, then help spread that knowledge to other GroupM agencies.

"We're doubling down on Essence as a growth engine for GroupM and WPP," GroupM Global CEO Kelly Clark said, calling the shop "the tip of the spear in terms of innovation across the group."

"Essence is currently a smaller agency, and therefore in some ways is nimble, adaptive and really able to act on changes and opportunities," he added.

The Target account, previously housed inside GroupM as Team Arrow, will now be split between Essence offices in New York and Minneapolis, where Target is headquartered. Team Arrow's 100 staffers and CEO Jason Harrison will become part of Essence.

Kristi Argyilan, senior VP-media, guest engagement and measurement at Target, said the brand can take a more progressive approach to marketing with a new emphasis on data and analytics. The brand spends more than $570 million in media billings annually, Essence said.

"We've gone beyond a category-driven approach to focusing on the sales that we want to drive and the guests who are resonating most with our storytelling," she wrote in an emailed statement. "It's also given us insight beyond just how marketing is driving sales; we now understand its larger impact on sales, distribution and pricing."

NBC Universal will also be moving under Essence from Maxus, which GroupM merged with MEC as part of its plan to increase its focus on Essence. Managing director of Maxus Los Angeles Pam Sullivan and 230 Maxus employees will become part of Essence to handle the account. NBC Universal spends more than $900 million in media billings annually, Essence said.

Essence will be looking at granular data like whether a consumer walks into a store or attends a concert. For a client like NBC Universal, which owns Universal Pictures, that could involve figuring out what kind of marketing exposure it takes to get a person into the theater to see a movie.

"There are much more important indicators than people's age or gender or where they live that start to indicate where their passion points are and how they feel about brands, how they respond to messaging," said Andrew Shebbeare, Essence co-founder and chief product officer. "And we're in an era where we can start to trigger off those points in a much more actionable and precise way."

Essence Global CEO Christian Juhl said his agency will be looking to figure out how to apply some of its digital practices to analog media channels.

"For us, it's how do we create an environment that looks like a private marketplace, or how do we provide a solution that meets everybody's needs so we can really look at what's effective in media?" he said. "I think that's ultimately what everybody is going to want. It's just understanding how these things work together. If we can't measure it at the granular level, it's really hard to prove what's effective."

More changes ahead at GroupM
Recent months have brought a slew of new hires and consolidations at GroupM, including the MEC combination with Maxus as well Neo@Ogilvy with Mindshare. More are coming, GroupM's Clark said.

"There will be more change -- I mean that in a positive sense," he said. "I do want to bring in new points of view and different experiences into our company. I also want to give our people an opportunity to learn new things, take on different challenges, and I think that's healthy for an organization as long as it's well-planned and succession happens in an orderly way."

Clark added there was no news to report on details of the merged MEC and Maxus, which has yet to be named, though said GroupM was "pleased" with how the integration was going so far.

"We're just working our way through getting the right people in the most motivating roles and working through the integration with clients," he said.