• by Erik Sass , Staff Writer @eriksass1, December 10, 2010

In yesterday's post I talked about the potential (or lack of potential) for social media to help boost search marketing revenues -- but I didn't get into the numbers, so today I thought I would look at some figures which might be relevant to the discussion. Although there's no way to do a decisive analysis in, I'm hoping to at least get a handle on possible correlations between social media, overall Web traffic, search usage, and the part that really matters: money.

The first question is whether an increase in simple Web traffic (overall, including social and everything else) has been correlated with increased search activity. This would seem to be a reasonable assumption, given the continued dominance of search as a means for navigating the Web -- and it does indeed appear to be the case.

From 2007-2010, the total U.S. Internet population increased 4.7% from 211 million to 221 million, according to eMarketer. Over the same period, the average amount of time spent online by U.S. Internet users increased 72% from 11 hours per week in 2007 to 19 hours per week in 2010, according to figures compiled from ComScore, Nielsen, and the University of Southern California's Annenberg Center. Meanwhile, U.S. search volume increased 66% from 9.9 billion queries at the core search engines in July 2007 to 16.4 billion in June 2010, per ComScore. These numbers (66% and 72%) are close enough to suggest that search volume is correlated with time spent on the Internet (with the number of Internet users a less important but still contributing factor).

The next question is how much the increase in total time spent on the Internet is due to increasing time spent on social media. Again, there would appear to be a correlation here. Taking the big dog of social media as a proxy for overall usage, the average time spent on Facebook by U.S. users jumped 132% from 180 minutes per month in March 2007 to 419 minutes per month in March 2010, according to Nielsen. Meanwhile the total number of U.S. users soared 440% from 21 million unique visitors in March 2007 to 114 million unique visitors in March 2010; in proportional terms, that represents a jump from 10% to 51.5% of the total U.S. Internet population.

These increases -- both in the number of users and the time spent on social media -- far outstripped the overall growth rates for the Internet population and time spent on the Internet at large. In this light, it seems reasonable to conclude social media (especially Facebook) is one of the main drivers of overall growth. And indeed, the proportion of total U.S. online time occupied by Facebook increased from 1.25% in March 2008 to 9.9% in August 2010, according to ComScore.

However, to connect the dots between social media and search we have to look at the prevalence of search behavior within social media. Here, there again appears to be a link between increasing social media use and increasing search behavior. According to ComScore, the number of search queries on Facebook increased 403% from 121 million in May 2008 to 609 million in May 2010. This growth rate exceeds the percentage growth in the number of Facebook users over the same period, which rose 260% from 36 million in May 2008 to 130 million in May 2010. Again, search volume in the Facebook ecosystem seems to benefiting both from an increase in the number of users and an increase in average time spent on the site per user. Meanwhile the volume of "expanded search" queries, which includes all searches outside the main search engines, jumped 81% from 13.7 billion queries in July 2007 to 24.9 billion in June 2010.

In summary, expanded search is growing faster than core search (81% growth compared to 66% growth, over the last four years) and social media appears to be playing a key part in that, with the proportion of Facebook searches rising from 1% to 2.5% of all searches over the same period. In short, social media is indeed contributing to the growth of search volume overall.

So far, so good. But once again, all these stats just beg the question: can growth in these areas translated into increasing search marketing revenues? And here the picture is a little more fuzzy. While I don't have any definitive answers, one fact stands out in my mind: growth in the "non-core" search category (which includes Facebook and other social media) isn't correlated as strongly with increasing search marketing revenues.

Returning to some of the figures I cited yesterday, total search marketing revenues increased 40% from $4.1 billion in the first half of 2007 to $5.75 billion in the first half of 2010, according to the Interactive Advertising Bureau. Comparing the search revenue and search volume figures, that 40% revenue growth figure is in roughly the same ballpark as the 66% increase in "core" search queries over this period. But it's not really in the same ballpark as the 124% growth rate in "non-core" search volume -- meaning, searches taking place outside the main search engines -- over the same period (from 3.8 billion non-core queries in June 2007 to 8.5 billion non-core queries in June 2010).

Summing up, the non-core search category appears to be less correlated with search marketing revenue growth. And that, in turn, doesn't seem promising for social search, which falls in the non-core search category.