Clicks on paid search listings on Google were nearly double the number of organic clicks — but only on keywords with “high commercial intent” in the US, according to a Wordstream analysis released today. Sponsored results, the research from the software company found, represented 64.6% of clicks on SERPs for commercial searches, while organic clicks only accounted for 35.4%.

Wordstream defined “high commercial intent” by Google’s own standards, including keyword searches that trigger a Google Shopping box or Google Product Listing ad. The company came to its conclusions by looking at data collected across approximately 1,000 AdWords accounts in the last 60 days, gathering additional data from several dozen accounts.

The company attributed the high click-through rate on paid ads on commercial searches to Google’s continual addition of new ad products. These include product listing ads, click-to-call, bottom of page ads, site links, social extensions and local extensions.

Additionally, Wordstream says getting clicks on organic listings for these commercial searches is getting more difficult, going so far as to call the search giant’s battle on web spam “Google’s War on ‘Free’ Clicks.” This, the researchers speculate, is due to factors such as the Panda and Penguin algorithm updates, as well as Google’s withholding of referrer data when users are logged into Google when they search.