US digital advertising spending is estimated to hit $37.31 billion in 2012, thanks to a growth of 16.6 percent, according to estimates by
eMarketer. The real interesting story, however, is that Google is expected to reclaim the top spot in the digital display advertising space, from Facebook.

I say “reclaim” because Google was once ahead of Facebook in terms of market share. Back in 2010, Google’s slice of total digital display ad revenue was 12.1 percent, compared to Facebook’s 11.5 percent. Last year, however, Facebook passed Google, as both grew to 14.1 percent and 13.5 percent, respectively. This year, Google is expected to end up back on top, with an estimated 15.4 percent market share, compared to Facebook’s 14.4 percent estimate.

You can see this all better in the following table:

2012 emarketer ads percent Google expected to take back display advertising lead from Facebook this year

It’s worth noting that the three companies rounding out the top five after Google and Facebook are all expected to lose market share this year: Yahoo, Microsoft, and AOL. eMarketer expects these trends to continue for at least the next two years, with Google pulling further ahead, Facebook cementing its spot in second place, and the other three falling further away.

Combined, the five giants will take in $23.9 billion in ad revenue, representing nearly two-thirds of total digital ad spending this year. eMarkter’s predictions are based on the Interactive Advertising Bureau’s (IAB) data for the first two quarters of 2012. In fact, the firm lowered its projections because the digital ad spending market is approaching maturity faster than expected. That being said: “However, eMarketer’s outlook remains optimistic—despite slower percentage gains, big dollar growth will continue.”

Going back to just digital display ad revenue, here’s what eMarketer expects:

2012 emarketer ads raw Google expected to take back display advertising lead from Facebook this year

Google is expected to take home $2.31 billion in US display ad revenue this year, up 38.5 percent from $1.67 billion in 2011, while Facebook will earn an estimated $2.16 billion this year, up 24.4 percent from $1.73 billion last year. Thanks to both companies, the overall US display ad market will grow an expected 21.5 percent to $14.98 billion from $12.33 billion in 2011.

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