Olson, the Minneapolis ad agency with only one name, is on a multimedia buying binge these days.

On Monday Olson announced the acquisition of Toronto-based MyThum to give the agency its first office outside of the U.S. and mobile marketing expertise. Terms of the sale were not disclosed.

It is the third acquisition in the last eight months for the 19-year-old agency. In May 2010 Olson brought Denali Marketing, a customer-loyalty firm, into its operation and in December acquired Chicago-based Dig to deepen its public relations arm.

Thus, in the course of less than a year, the agency with Loring Park for a backyard has become international and bicoastal with 400 employees and annual revenues exceeding $70 million.

"We're incredibly confident with what we're building," said Olson CEO Kevin DiLorenzo when asked if the agency could be stretched thin in another economic downturn. "Even in the toughest of times, Olson has experienced dramatic organic growth."

MyThum brings $6.5 million in new annual revenue and 30 employees. It will maintain its Toronto presence with a client list that includes MolsonCoors, ticket seller Live Nation, Ontario Lottery Group, Ford Motor Co., Atlantic Lottery Corp., Sony and Sears Canada.

MyThum also gives Olson proprietary technology to connect brands and their customers through mobile devices.

"Mobile devices are no longer the third screen, they have become the first. And they're the only screen we carry with us," DiLorenzo said.

Michael Carter, MyThum's founder who will stay on as president of the firm under the Olson umbrella, said the rapidly changing demands from clients for mobile access forced him to look for a partner.

"We had to either acquire someone or be part of something that was bigger," Carter said. "It was the perfect time to see if we could take it to the next level."

Carter said mobile marketing is such a growth area because the likes of smart phones, iPads and other screen devices are almost always in the presence of customers and potential customers of a brand.

"Mobile marketing drives loyalty, brand awareness and allows the consumer to make purchases either in the store or on their [mobile] device," Carter said.

Olson and MyThum have only one client in common -- the hockey equipment company Bauer. But Olson also counts Target Corp. among its clients and Target recently announced that it was opening up to 150 stores in Canada in the next few years, which could be an opportunity for Olson's MyThum division.

John Purdy, professor of advertising and public relations at the University of St. Thomas, said Olson is moving in the right direction with its recent acquisitions.

"Olson has been pretty smart in a depressed advertising economy," Purdy said. "All three are growth areas and are consistent with an aggressive and smart direction."

In Dig, Olson acquired a fast-growing public relations firm whose client list included MillerCoors, the Wrigley Co., Southwest Airlines and Harley Davidson. Its headquarters are in Chicago, with smaller offices in San Francisco, Los Angeles, Milwaukee and New York.

With Denali, Olson brought aboard a veteran team of customer loyalty specialists and clients like Sun Country Airlines, Toys 'R' Us and Best Buy Co. Inc. Denali also brought with it a proprietary software program that allows it to track and analyze consumer behavior in detail.

"We've put together an impressive lineup. Now it's time to focus internally and deliberate a strategic plan," said DiLorenzo. "We've hit the pause button on acquisitions."

David Phelps • 612-673-7269