2013 was a banner year (pun intended) for programmatic media. Both participants in the ecosystem and the systems/platforms they are leveraging are starting to evolve as mechanisms for efficient deployment of performance-oriented ad dollars. eMarketer estimated nearly $3.4 billion in programmatic spend being delivered in 2013. RocketFuel's IPO, Criteo's IPO, mergers, acquisitions (SiteScout/Centro), and massive growth continues to demonstrate the power of programmatic media. But most of these firms are associated with DR advertising. Even private exchanges these days aren't proliferating due to a lack of brand dollars in the RTB ecosystem.

John Battelle, founder/CEO of Federated Media, saw the rise of programmatic coming from a mile away. Back in 2010, he realized that the number of people directly involved in selling largely undifferentiated display media was going to decline dramatically. At the same time, data about publishers' inventory was increasingly in the hands of the buyers, but not the sales force. In fact, that data was more likely than not owned by middlemen, leaving the publisher with no control. Given this situation, Battelle reasoned, publishers needed an automated platform to give them back control of their data. It turns out, that's …

The year of 2013 was very telling for retargeting, and there is a wealth of knowledge to reap from the advancements -- which include the early uptick in ad spending across various retargeting efforts, the massive increase in biddable inventory (via FBX), and Google and Microsoft's major announcements regarding data encryption. Consider the following key takeaways from 2013 when you plan your retargeting strategy: