Over the next few weeks I'll be doing a series of posts on broadband video advertising's key opportunities and challenges, based on briefings with industry players. Advertising has increasingly become the industry's business model of choice, so understanding its future development is critical.

Just as there are advertising networks for Internet display or banner advertising, there are now a number of independent ad networks dedicated to broadband video advertising. These ad networks perform a crucial role in aggregating and selling inventory, creating efficiencies for both publishers and advertisers alike. These are particularly critical functions given how fragmented video is online.

I recently had a chance to catch up with Tod Sacerdoti, CEO/co-founder of BrightRoll, a big independent video ad network, who's in the trenches every day and is as knowledgeable as anyone about today's market and key challenges. BrightRoll is focused on building a network of high-quality publishers offering advertisers full transparency about which sites their ads run on. It is flexible to support all formats, players and units and has served over 1 billion ads to date.

Though BrightRoll just introduced an HD in-banner ad unit, it generally shies away from pioneering new formats, leaving it to publishers to drive the market. Tod believes that technical leadership will be a key differentiator and so BrightRoll builds all its own technology in-house.

For ad networks, the size and quality of their publisher network is obviously critical. BrightRoll's sweet-spot are premium branded sites that it can sell for around $15-25 CPM. This is the middle part of the market, below the "super-premium" sites but above the vast amount of user-generated video which is tough to sell.

Tod breaks down the market's current 10 billion streams/mo. Of the 40% non-YouTube videos, about half of the streams are monetizable, yielding about 2 billion streams. Tod thinks about half of these are sold. Two reasons for such a high unsold ratio are that many premium sites are maintaining minimum CPM requirements and because there are usage spikes that create unsold inventory. One of BrightRoll's key goals is to get the "unsold" server call from premium sites which want to maximize yield on usage spikes.

From Tod's standpoint a big challenge remains lack of standards, and therefore the reluctance of big publishers to fully integrate with ad networks. The IAB has been focusing on video standards which are expected soon. I have thought for a while that broadband video advertising will be driven by big brands diverting budget from TV ad spending. This contrasts with search, where Google in particular has relied on tens of thousands of smaller, ROI-focused advertisers. Tod sees it the same way and therefore is focused on driving high-quality online reach that brands require, along with reliable tracking and reporting.