• by Gavin O'Malley  @mp_gavin, September 12, 2011

Out to secure its position as the Web's top video ad network, Tremor just secured an impressive $37 million in financing.

Tremor serves in-stream and in-banner video ads across a network of mid-tier and premium sites from WWE.com to NYTimes.com. But like many Web-based ad networks, the company sees great potential for growth in international markets.

"We plan to use this capital to aggressively increase our leadership role here in the U.S. while expanding globally," Bill Day, CEO of Tremor Video, said Monday.

Led by New York City-based W Capital Partners, additional participants in the round included Keating Capital, Canaan Partners, Draper Fisher Jurvetson Growth, General Catalyst Partners, Meritech Capital Partners, Singapore's EDBI, Time Warner and SAP Ventures.

This past May, Tremor ranked second among all platforms in driving ad impressions online -- and first among video ad networks -- with 700.8 million ad views, according to comScore.

Tremor also ranked as the top video ad network in terms of potential reach of the total U.S. population -- at 47.1% -- followed by BrightRoll Video Network -- at 42.1% -- and Break Media at 40.4%.

Time spent watching videos ads totaled more than 2.0 billion minutes during the month, with Hulu delivering the highest duration of video ads at 560 million minutes, comScore found.

Video ads reached 45% of the total U.S. population an average of 34 times during the month, while Hulu also delivered the highest frequency of video ads to its viewers, with an average of 48 over the course of the month.

Having acquired ScanScout and Transpera in the past year, Tremor has aggressively sought expansion in the interactive video space.

With the launch of Video Hub this past May, Tremor Video recently sought to improve the network model by helping brand advertisers monitor video campaign performance in real-time. VideoHub analyzes various video signals in an effort to determine which factors are the most important in improving engagement and brand lift, among other factors.

In April 2010, Tremor secured $40 million in venture capital funding led by Draper Fisher Jurvetson Growth Fund, with participation from DFJ and Triangle Peak Partners. Canaan Partners, Meritech Capital Partners, and SAP Ventures also participated in this financing.

Tremor reported achieving profitability at the end of 2009 -- doubling the size of its video advertising network from 2009 to 2010.