Will you tweet today? Like something on Facebook? Watch a YouTube video? The result of social behaviors such as these has created what Forrester is calling the “database of affinity,” essentially the data catalog of what consumers like, collected by observing social behaviors. The promise of the database of affinity is powerful — it’s the Holy Grail for powering more accurate brand advertising — but exploiting it will be challenging, notes Forrester Principal Analyst Nate Elliott in a new report out today. Any vendor hoping to serve up this database to marketers will need to offer not only a collection of affinity data from across the social world but also the analysis tools and ad formats that will actually allow marketers to turn this affinity data into dollars.

So as the big players (Facebook obviously, but Google as well) continue to move aggressively to crack the value of this database, the question hangs: Who will win the battle? “While it’s Facebook’s birthright to win the race for monetizing the database of affinity — after all, it practically owns the trademark on “liking” something — ultimately, it will be Google that reaches the finish line first,” writes Elliott in the report. While this call may seem counterintuitive given Facebook’s current status and the news around its data partnerships, Forrester believes Google is not only handily beating Facebook in building and analyzing this database but is ahead in the affinity data it already possesses because of the success of Gmail and some of the review sites it owns (as seen in this blog post). As a result, notes Elliott, as Facebook continues to wrestle with privacy challenges, Google will use its affinity data to power engaging ads in many media.

The new research also outlines the evolution of affinity marketing. By 2018, the database of affinity will reach its peak influence — and start to disrupt a large portion of brand advertising when vendors learn how to use this data to target offline ads. “In five to seven years, many of the ads you see on TV will be decided by the affinities you declare in social media,” writes Elliott.

To learn more about this research, visit the full report: How To Exploit The Database Of Affinity.