The company says the firms are integrating OCR into their platforms through an application programming interface so that they can access the measurement data and monitor their online advertising effectiveness.

Adap.tv, DataXu, FreeWheel, Innovid and LiveRaila are among the other firms signed up to the initiative with Set, TubeMogul, Turn, Vindico and Zedo rounding up the list. VideoHub was the company’s first partner, signing up in 2011.

Amit Seth, EVP global media products at Nielsen, said: “The platforms that sit between the buy and sell sides are the nerve-center of online advertising, where advertisers and publishers extract the maximum mileage out of their spend and inventory respectively.”

• In other news, Nielsen’s financial arm has sold $800m-worth of senior notes in the 144a private placement market. JP Morgan and Goldman Sachs were the joint bookrunning managers for the sale.The size of the deal was increased from an originally planned $750m and represents 4.5% of the notes it owns, which are due to mature in 2020.