LONDON: Marketers should adapt their UK search advertising strategies for smartphones, tablets and computers given the varying roles these channels play in the purchase process, new figures show.

Kenshoo, the digital technology firm, looked at data from retailers using its search advertising platform, and found computers delivered 72% of clicks, with tablets on 15% and mobile phones on 13%.

In terms of cost-per-click, mobile phones offered the best value at £0.16, rising to £0.27 for tablets and £0.32 for personal computers.

When looking at the share of conversions, however, computers yielded 80%, suggesting shoppers remain more confident about buying goods via this route. Their conversion rate stood at 5.2%.

Mobile phones posted the lowest totals on both these metrics, supplying only 3% of transactions in volume terms, and a 1% conversion rate. These figures hit 16% and 5% respectively for tablets.

Further, tablet users recorded the highest average order value when making purchases, on £85.55. Their counterparts using phones spent £77.80 per transaction, standing at £75.94 for computers.

"Tablet shoppers are a gold mine," said Chris Ward, managing director, EMEA, at Kenshoo. "They convert at higher rates and spend more money than the average online shopper.

"The savviest retailers are breaking out their keywords, ads and landing pages by computer, phone and tablet to better control budgets and bids."

Kenshoo's data set drew on 450m paid impressions and clicks on search engines including Google, Bing and Yahoo. The sales generated through this route reached £40m over 2011 and 2012.

The featured retailers spent 20% more on search ads this year than last year, the study added.

Data sourced from Kenshoo; additional content by Warc staff