• by Laurie Sullivan , Staff Writer @lauriesullivan, August 31, 2011

As behavioral targeting through ad exchanges grows, marketers want a method to confirm that they're getting what they've paid for. This trend created opportunities for companies like DoubleVerify to monitor delivery of ads.

Earlier this week, the company reported securing another $33 million in venture capital funding, bringing total financing to nearly $47 million. With this round, Bob Nye of JMI Equity and Dennis Phelps of Institutional Venture Partners joins the company's board of directors.

In other examples of a possible boom in ad verifiers, Click Forensics bought Adometry in March, and in August comScore acquired Seattle-based AdXpose, formally Mpire, for $22 million in a mostly stock-based deal. AdXpose CEO Kirby Winfield stayed on with the company to run the business.

AdXpose allows advertisers to verify and optimize billions of campaign data points captured in real time.

Both DoubleVerify and AdXpose will compete against AdSafe, another ad verification service, as well as Adometry. In July, Adometry released the Attribution Index, which scores ad campaign performance to help agencies and marketers predict which combination of placement and creative will drive future conversions.

As for DoubleVerify, whose clients include Bank of America, Wal-Mart and Wells Fargo, the company verifies more than 40 billion impressions monthly. Within the past 12 months, the company has jumped from 30 employees to 160 today, with 50 more being added to offices in New York, Israel, and London by the end of 2011.