Online video ad network TidalTV has raised $16 million in a second round of funding.

The New York based startup offers what it calls “zero waste advertising.” In other words, it optimizes the distribution of in-stream ads (basically commercials that run before, after, or during the video) and interactive ads so that companies maximize their reach to the audience that they’re looking for. In fact, TidalTV says that if its network doesn’t allow your ad to reach the audience that you want, you get your money back. It’s also looking to expand to “all video delivery platforms,” not just the web.

That sounds like a different model from the one TidalTV was pitching when it raised its $15 million two years ago. Back then, it said it would offer “the best in professionally produced, branded programming,” but it seems like video ad startups are doing better than video websites — for example, BrightRoll recently told us that its ads reach 53 million people each month, and more importantly that it has been profitable for the last 12 months.

The new funding comes from Comcast Interactive Ventures and existing investors New Enterprise Associates and Valhalla Partners.