• by Laurie Sullivan , Staff Writer @lauriesullivan, July 10, 2015

Search marketers seeing a shift from desktop to mobile clicks on paid-search advertisements might find the answer in Gartner's latest PC numbers.

Worldwide PC shipments fell 9.5% to 68.4 million units in the second quarter of 2015, compared with the year-ago quarter, according to Gartner. The research firm calls it the steepest PC shipment decline since the third quarter of 2013. Overall this year, PC shipments are projected to decline 4.4%.

Gartner's analysts attribute the decline to "the price hike of PCs, the "end of Windows XP support," and "the Windows 10 launch scheduled for 3Q15." While it's difficult to say whether these factors directly influence the trend of consumers moving from PCs to mobile devices, the fact remains an increasing number of people spend more time on mobile devices today than in the past.

IgnitionOne notes this trend in its second-quarter 2015 search report published Thursday. The company sees "a shift in user search traffic from desktop/tablet to mobile phones combined with rising CPCs," according to the report, which also notes "more demand and improved performance resulted in an overall increase in mobile search spend."

Mobile devices continue to drive search advertising growth, according to IgnitionOne's report. Marketers, following the uptick in searches and clicks, increased the amount spent on mobile advertising between April and June 2015, compared with the prior year. Growth for tablets rose 22%; and phones, 71%. Tablets took 41% and phones took 59%. The click-through rate rose 17% for tablets and 28% for phones.

IgnitionOne also notes a rise in programmatic use. Spend rose 33% in the quarter, compared with same clients measured for Q2 2014. Impressions rose 60% and spend is up 47%, sequentially.

In Gartner's report, Lenovo maintained the top position in worldwide PC shipments in the second quarter of 2015, but even the leader suffered a year-on-year shipment decline for the first time since the second quarter of 2013. EMEA, Latin America and Japan were tough regions for Lenovo, as the company experienced double-digit shipment declines.

HP also experienced a shipment decline after five consecutive quarters of PC shipment growth. HP showed a steep decline in EMEA, which Gartner attributes to an impact on currency changes. The company was also impacted by tight inventory controls in the consumer market before the Windows 10 launch.