Google’s push to drive consumers to click on Google Shopping ads by increasing ad space for its visually oriented ads is working; Google Shopping ads accounted for 76.4% of U.S. retailers’ search ad spending in January and February, according to search marketing analytics firm Adthena Ltd. Those ads generated 85.3% of all clicks on AdWords and Google Shopping campaign ads. Google text ads make up the remaining share.

In the United Kingdom, Google Shopping ads accounted for 82.0% of retailers’ search ad spending in January and February, according to Adthena. Those ads generated 87.9% of all clicks on AdWords and Google Shopping campaign ads.

Adthena’s report is based on its analysis of 40 million ads from 240,000 U.S. and U.K. advertisers.

In the United States, retailers spent 37.8% of their search ad budget on desktop PLAs, which produced 43.5% of their search ad clicks. Retailers spent 38.5% of their search ad budget on mobile PLAs, which produced 41.8% of their search ad clicks.

In the United Kingdom, retailers spent 47.2% of their search ad budget on desktop PLAs, which produced 52.3% of their search ad clicks. Retailers spent 34.8% of their search ad budget on mobile PLAs, which produced 35.6% of their search ad clicks.

U.S. retailers are allocating a larger share of their search ad budgets on mobile PLAs even though more shoppers are clicking on desktop PLA ads. That likely reflects the products consumers are searching for, says Ashley Fletcher, Adthena’s vice president of marketing. “Mobile PLAs offer shoppers a rich user experience on a mobile device,” he says. “But because some products consumers might be searching for are higher-ticket items, it isn’t surprising that they might complete their purchase on a desktop.”

For instance, a consumer shopping for a $2,000 TV might use his phone to research prices while in a store or on his commute. But given that it is a large purchase, shoppers often wait to finish their research and click and buy on a desktop, he says. That helps explain why consumer electronics retailers, which often sell high-ticket items, devoted 86.0% of their search spending to PLAs, which was the largest share among the nine product categories Adthena examined.

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There’s good reason for that spending, the ads have a positive click-to-spend ratio.

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Non-brand keywords account for a much larger share of Google Shopping ads than branded search terms, which are searches that include a company or product name. Only 33.6% of U.S. merchants’ Google Shopping ad spending is on branded keywords, with non-brand keywords remaining 66.4%. That’s likely due to broad diversity of generic, product-based search terms that retailers need to compete on, Fletcher says.

“Retailers have to be strategic in how they approach non-branded search terms because they can’t win on everything,” he says. “That means they need to figure out what terms they want, or need, to win at.”