• by Laurie Sullivan  @lauriesullivan, January 30, 2014

Video ads on YouTube welcomed a steady stream of viewers tuning in to Google's earnings call Thursday, where Nikesh Arora, SVP and chief business officer, detailed results from the 2013 fourth quarter, touching on how product listing ads gave paid-search clicks a boost.

Google reported that profit climbed to $3.38 billion on rising ad revenue. Overall, revenue rose 17% to $16.86 billion for the quarter ended Dec. 31, 2013, compared with the year-ago quarter.

Paid-search clicks got a boost from product listing ads, rising 31% year-on-year and 13% sequentially. The cost per click fell approximately 11% in the quarter, compared with the year-ago quarter, and 2% sequentially. Traffic acquisition costs rose to $3.31 billion in the fourth quarter of 2013, compared with $3.08 billion in the fourth quarter of 2012.

Google accounted for 32.84% of the digital ad budgets spent by marketers worldwide in 2013 -- up from 31.5% in 2012, according to eMarketer. The global digital ad market grew by 13% to $117.6 billion in 2013, up from $104.04 billion in 2012.

One focus leading to the increase has been helping brands build a presence on the Internet -- specifically YouTube, per Arora. Performance advertising relies on clicks to determine success, but brand advertising is a bit more difficult to quantify when it comes to measurements.

During the quarter, Google appointed senior P&G exec Kirk Perry to lead the development of services that support brand advertising. The strategy continues to focus on building content for the Web, rather than taking television ads and transplanting them on YouTube. The site attracts more than 1 million viewers monthly.

Mobile has not become less important for Google. The Motorola Mobile segment -- the division Google announced selling to Lenovo earlier this week -- generated $1.2 billion or 7% of consolidated revenue in the fourth quarter of 2013, compared with $1.51 billion or 11% of consolidated revenue in the fourth quarter of 2012.

Google took 53.17% of the worldwide mobile ad market share in 2013 -- up from 52.36% share in 2012, according to eMarketer. The overall mobile ad market worldwide grew 89.2% to $16.65 billion in 2013 -- up from just $8.8 billion in 2012, the analyst firm estimates.

Google-owned sites generated $10.55 billion, up 22%, in the fourth quarter of 2013. Partner sites generated $3.52 billion in revenue, up 3% compared with the year-ago quarter.