• by Laurie Sullivan  @lauriesullivan, January 15, 2015

Mobile conversions make up only about 30% of all search conversions, although mobile marketing and the metrics to quantify campaigns are finally reaching parity with desktops, per a study from Marin Software. This means that advertisers still have issues with mobile attribution, as well as converting a mobile search click to a mobile conversion -- which continues to hold back many brands from forming that one-on-one relationship with consumers.

While smartphone spend outpaces smartphone clicks and conversions, Marin Software sees that tablet devices make up only 8.4% of ad spend, but over 15% of clicks and 13% of conversions. The insights come from Marin Software's Q4 2014 Performance Marketer's Benchmark Report, which looks at search, social, and display performance data by device.

Overall, about half of what marketers spend on search campaigns is attributed to mobile, but this has the potential to become so much more, said Brian Kaminksi, market research analyst at Marin Software. The industry continues to have trouble tracking, attributing and tracing mobile conversions. It's still not as easy to make a purchase on a mobile device as it is on desktop, where the consumer has access to a keyboard.

When consumers search for products on a desktop, they typically will buy it from the desktop. Consumers looking for products on a mobile device typically want to compare prices or find a physical location in which they can buy the product in a store.

comScore notes that consumers spend one in three minutes of all online browsing time on mobile devices. A recent report revealed that among adults 18 to 24, 70% of all retail content is viewed from a mobile device, per Marin, citing Millennial Media.

Marin's study suggests that from Q1 to Q2 2014, mobile activity grew 19%, with smartphones growing 27.8%. Desktop activity dropped 5.5%. All this signals a shift in consumer behavior from desktops to smartphones and tablets, with an emphasis on cross-device viewing.

There is another hurdle. Only 27% of digital marketers say online ad campaigns are totally integrated across other digital channels, per Marin. Only 57% of marketers in the U.S. said they optimize campaigns for mobile when they can, but do not make mobile a focus of their programs. Some 1.75 billion people worldwide will have used a smartphone by the end of 2014, according to eMarketer.

Display advertisers demonstrate behavior similar to that of search, while smartphone growth YoY has been even more extreme for display than search. Smartphone spend share actually fell slightly from last year. There a heavier mobile device focus for display than there is for search, per the report.

Nearly half of marketers' budgets in Q3 on mobile devices went to display, and also made up over half of clicks. Simialr to Q3, in Q4 2014, there was a discrepancy between the amount marketers spent on smartphones and tablets, compared with clicks, where tablet clicks outpaced tablet spend, and vice versa for smartphones, per the report.

"Smartphone User" photo from Shutterstock.