(Bloomberg)—Google Inc. is making it easier to know when ads are effective, even if they spark sales days after they’re viewed and from different gadgets.

The company is rolling out tools that gauge how well advertisements work across smartphones, tablets and desktop computers, according to Neal Mohan, vice president for video and display advertising. The service can measure customer responses that, for example, start as an ad click on a mobile phone and end with a purchase from a personal computer.

“It’s not just one device—90% of consumers move from device to device throughout the course of the day,” Mohan said. “A consumer might see a video ad on a desktop at work, but they may not actually make a purchase until they’re at home on their laptop or tablet.”

The new service is available from Google’s DoubleClick unit, which serves ads on the Internet, though is available for marketing bought from other companies, as well. The service previously was available on Google’s AdWords feature, which businesses use to buy placements next to search results.

The Mountain View, Calif.-based company is stepping up efforts to help marketers target users on mobile gadgets as consumers increasingly use smartphones or tablets to fire up apps or visit websites. Users in the U.S., Japan and other countries have shifted more than half their Internet searches to handheld devices from PCs, the company said last month.

Google on Wednesday also released a service to make it easier to sell so-called native ads—marketing meant to blend in particularly well with the content around it. The company also is making it easier to quickly buy and sell spots on premium websites.