The online advertising marketplace has rebounded, and so has the ad network business. Many ad networks have become more specialized, such as Feedburner which focuses on the inventory available in RSS feeds or Tacoda, which offers behavioral targeting within its network. Overall, the networks are still working to grow their available inventory while struggling to survive in the face of inventory monoliths Yahoo and Google.

With so many new players and product offerings in a revitalized sector, it's increasingly confusing for media buyers to figure out where the greatest value lies. They also face the difficult task of discerning where there is real value among multiple players with similar positioning and a great deal of hype. Most importantly, since the networks tend to promote leaving optimization in their hands, marketers are left to determine the most advantageous deal terms.

Let's explore how marketers can best work with ad networks to maximize efficacy.