The layouts of smartphone and desktop search engine results pages (SERPs) are the reason for such differences, according to Marin, which pointed out that a smartphone SERP will often only show one ad at the top of the page, while the same results page on desktop will show three or more. Of course, advertisers should remember that CTRs aren’t enough for mobile ad measurement.
eMarketer expects 129.0 million US smartphone users to search via mobile browser or app on their phones this year, representing 78.0% of smartphone users and 40.7% of the population. By 2018, total smartphone searchers will reach 200.5 million—91.1% of smartphone users and 61.1% of the population. Read the rest at eMarketer.