Google reported quarterly earnings and revenue that missed analysts' expectations, as foreign exchange and falling ad prices weighed on the company.
Reporting Thursday after the bell, the technology giant posted fourth-quarter adjusted earnings of $6.88 per share, up from $6.00 a share in the year-earlier period. Revenue rose to $18.1 billion from $16.86 billion a year ago.
Wall Street had expected Google to report earnings of $7.11 per share on revenue of $18.46 billion, according to a consensus estimate from Thomson Reuters.
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The company's stock initially fell more than 3.5 percent in after-hours trading, but moved to a more than 1 percent gain as the earnings call progressed.
Google CFO Patrick Pichette said on the earnings call that revenue was hurt by a combination of a strong U.S. dollar and Nexus 6 inventory problems that meant the company was unable to meet forecast demand—he originally pointed to the Nexus 7, but then later clarified his statements.
He added that "unusual charges" affected the company on the expense side—these included compensation charges and real estate write downs.
Pichette said 2014 was "a year of significant investment growth," adding that the company will "continue to seek a healthy balance between growth and discipline."
In Google's earnings news release, Pichette said the company achieved the $18.1 billion revenue figure "despite strong currency headwinds."
Google said that its fourth-quarter revenues would have been $541 million higher if foreign exchange rates had remained constant form the previous quarter. On the call, Pichette said the net revenue impact of a strong dollar cost the company $468 million.
The tech giant said its aggregate paid clicks increased about 14 percent over the fourth-quarter of the prior year, and increased approximately 11 percent compared to the last quarter.
As for average cost-per-click, the company said this number decreased about 3 percent over the year-ago period, and also decreased approximately 3 percent over 2014's third-quarter. Pichette pointed to foreign exchange, geography, and device mix to explain the decrease.
In other words, the average price of Google's digital advertisements continued to fall, at the same time that the company saw an increase in people clicking on those ads.
Still, Pichette said the company "saw continued strength in our core advertising business."
Omid Kordestani, Google's chief business officer, said YouTube now has a billion users, and that watch time has grown 50 percent compared to the prior year. The platform's mobile revenue rose more than 100 percent, he added.
As for other platforms, Kordestani said Google for Work had a "great quarter," the cloud platform is making "good progress," and Google Play has seen internal growth at an "unprecedented speed."
He also reported that Chromecast continues to be a "hit" (with a 60 percent increase in usage since its launch), and Chromebooks are enjoying "strong success" in schools.
In regard to Google search, Pichette declined to comment on Mozilla switching to Yahoo as a partner, but he said that people can still find the search engine online.
Google said it had $64.40 billion worth of cash, cash equivalents, and marketable securities as of Dec. 31, 2014. Pichette said that he had nothing to announce on Thursday regarding a potential capital return.
Google has underperformed relative to the Nasdaq, recently. The stock has fallen nearly 6 percent in the last three months, while the index has climbed about 3 percent.
Despite its struggles, including in monetizing the user transition from desktop to mobile devices, the Internet and technology giant has started 2015 with a flurry of activity. While search and advertising still form the core of its business, Google has continued to delve into unrelated ventures this year.
The company announced on Tuesday that it would expand its high-speed fiber-optic network, or Google Fiber, to four new metropolitan areas in the United States. It also contributed to a $1 billion funding round for Elon Musk's SpaceX, which the aeronautics company announced last week.
—CNBC's Josh Lipton contributed to this report.