• by Erik Sass , Staff Writer @eriksass1, September 8, 2011

Google's paranoia about Facebook is an established fact; much as Google execs may claim Google+ isn't intended to compete with Facebook, it's hard to take the assertion at face value, considering how many areas of overlap there are between the new social network -- sorry, I mean "suite of social tools" -- and Facebook.

It's true that Facebook has laid hold of an unprecedented share of Internet activity in terms of time spent and user engagement. But these metrics don't necessarily equal revenue and profitability, and on that note, the most recent projections from eMarketer have me wondering (not for the first time) whether Google's Facebook fixation is entirely rational.

According to eMarketer, Google's total U.S. revenues will grow an impressive 27.3% from $10.03 billion in 2010 to $12.77 billion in 2011; assuming a conservative growth rate of 25%, global revenues (including the U.S.) could increase from $29.32 billion in 2010 to $36.65 billion. This certainly seems plausible enough, considering total (global) first-half revenues jumped 29.4% from $13.6 billion in 2010 to $17.6 billion this year.

Of course, the lion's share of Google's revenue still comes from search advertising -- $10.92 billion or 85.5% of the total in 2011, per eMarketer -- and importantly, its share of that crucial market is still growing. In short, Google remains the dominant player in what remains the dominant discipline in Internet advertising. Indeed, Google's share of the total online advertising market also continues to increase, from 38.5% in 2010 to 40.8% this year.

Meanwhile, according to eMarketer Facebook's U.S. revenues will grow 81% from $1.21 billion in 2010 to $2.19 billion in 2011, as global revenues roughly double to $4.05 billion. These are admittedly big numbers, but just as clearly nowhere near Google's: Facebook's U.S. revenues in 2011 will amount to 17.1% of Google's, up from 12.1% in 2010, and its share of the U.S. ad market will increase from 4.6% in 2010 to 7% in 2011. Globally, Facebook's revenues in 2011 will amount to perhaps 11% of Google's total.

Now, there's no question that Internet advertising is a dynamic, fast-changing marketplace, and Google's top execs aren't paid to be complacent about potential threats, even if they appear small for the time being. But the fact remains that Facebook, for all its massive user base and high level of engagement, is attracting roughly one-tenth the ad spending going to Google -- hardly a terrifying spectacle.

There is also the possibility (very real, to my mind) that, even as Google continues to expand, Facebook may be reaching some natural limits on its growth, both in terms of new user recruitment and increasing engagement among existing users. It's way too soon to say, of course, but as noted in some of my previous posts, there is some data hinting that Facebook's novelty may be slowly wearing off.

For example, the average number of page views per user slipped from 1,423 per month in January 2011 to roughly 1,200 in June 2011, according to calculations based on figures from Nielsen, comScore, and Pingdom. And according to Experian Hitwise, the proportion of U.S. adults who visited Facebook 16 or more times in the past 30 days fell from 57% at the end of January 2011 to 52% at the end of April. A recent survey of 100,000 Facebook users in 27 markets around the world (including the U.S., U.K., and Canada) by Trendstream's GlobalWebIndex found "sharp declines" in activities like status updates, content-sharing, messaging and installing apps. Facebook messaging in the U.S. declined 15% from June to July, while the number of people joining groups declined 10% over the same period. The findings were striking enough that the GWI researchers concluded "time has wearied users of Facebook," adding, "The trend is even more pronounced among U.S. college educated 20somethings, the original users of the platform."