• by Laurie Sullivan  @lauriesullivan, January 19, 2012

Google co- founder and CEO Larry Page said during the company's Q4 2011 earnings call Thursday that Google+ now supports more than 90 million users. On Wednesday Google introduced a feature that allows users to share directly from Google+ search results and contribute to a stream.  

Page also said there are 250 million Android devices activated -- up 50 million since November. In two days during the holidays, 3.7 million Android devices were activated, and more than 11 billion downloads from Android Market. 

Aside from Android, Page also released numbers related to other Google businesses. Display advertising reached an annualized run rate of more than $5 billion. Advertisers are spending more than 130% on the DoubleClick ad exchange, and Gmail has 350 million active users.

While Page touted other Google businesses, including enterprise, paid search continues as the company's core revenue generator. Aggregate paid clicks -- those related to ads served on Google sites and the sites of the company network -- rose 34% in Q4 2011 compared with the year-ago quarter, and 17% sequentially. The average cost-per-click -- those related to ads served on Google sites and the sites in its network -- fell 8% in Q4 2011 compared with the year-ago quarter, and 8% sequentially.

Traffic acquisition costs -- revenue shared with Google’s partners -- rose to $2.45 billion in Q4 2011 compared with $2.07 billion in Q4 2010. TAC as a percentage of advertising revenue was 24% in Q4 2011, compared with 25% in the fourth quarter of 2010.

The majority of TAC is related to amounts ultimately paid to companies supporting its network, which totaled $2.01 billion in Q4 2011. TAC also includes amounts ultimately paid to certain distribution partners and others that direct traffic to Google's Web site, which reached $442 million in Q4 2011.

Google earned $2.7 billion, or $8.22 per share, during Q4 2011 -- up 6% from $2.5 billion, or $7.81 per share, during the year-ago quarter. Analysts expected earnings of $10.51 per share on net revenue of $8.4 billion, according to consensus estimates.

Analysts may have been disappointed, but marketers were not. When it comes to marketing, Google's earnings numbers were in line with expectations, according to Roger Barnette, president of IgnitionOne, a digital marketing company. "The increase in revenue is really quite impressive," he said. "The numbers show an extremely healthy and positive quarter for Google, although the analysts weren't happy because the company missed EBIDA."