“After a five-year sabbatical on the supply-side, agency media vet Tim Spengler is back on the demand-side, sort of,” MediaPost reports. “Spengler has joined Dentsu Aegis Network as president of its M1 unit, according to an alert sent from his LinkedIn profile.”

The report adds: “M1 is a platform created by DAN’s Merkle unit that leverages the data-based agency’s considerable identity graph to help publishers make a better market out of their advertising inventory by leveraging ‘people-based’ targeting.

“The unit, which was conceived by Merkle’s John Lee, who serves as president-global of M1, is a similar concept to Spengler’s recent role as president-chief revenue officer of Simulmedia, which leverages people-based targeting to make TV advertising more effective for advertisers and networks.”

Spengler was prevously a longtime media executive at a number of Interpublic agencies, including global CEO of Magna and president of Initiative.