• by Laurie Sullivan  @lauriesullivan, July 16, 2015

Google reported Thursday the aggregate cost per click (CPC) across its network fell 11% in the second quarter of 2015, but was offset by the increase in ad volume.

The number of paid clicks rose 18% year over year (YoY), with the help from mobile, YouTube TrueView, and product listing ads.

Clicks on Google sites also rose 30% YoY, but clicks on other Google network member sites fell 9%, hurt by quality-control efforts and AdSense research. CPCs on Google's Web sites fell 16%, and on Google's Network Member Web sites CPCs fell 3%.

"The CPC gap between desktop and mobile continues to narrow, said Ruth Porat, CFO of Google, during the earnings call Thursday.

Google reported during its second quarter 2015 earnings call that revenue during the quarter rose 11% to $17.7 billion from a year earlier, with net revenue, excluding payments to advertising partners, rose to $14.35 billion. The company generated a profit of $6.99 per share, compared with $5.98 a year ago.

Google got a boost from mobile, programmatic media buying, and YouTube TrueView ads. The average viewing session from mobile on YouTube is 40 minutes, according to Omid Kordestani, chief business officer. He said the number of advertising running video ads on YouTube rose 40% in the quarter, compared with the year-ago quarter, and for the top advertisers the average spend rose more than 60%.

Kordestani attributes YouTube's growth to the more than 1 billion users watching "hundreds or million of hours." He also said advertisers can buy TrueView ads programmatically through Bid Manager. This helps content creators build the next generation of media companies and channels. "The number or channels earning six figures per year is up 50% year over year," he said.

Overall, Google's revenue from advertising rose 11% to $16 billion in the second quarter ended June 30, up 11% from the year-ago quarter. Other revenue fell 17% to 1.7 billion.