• by Laurie Sullivan  @lauriesullivan, March 30, 2011

Google is working to more accurately target ads to email content in Gmail. The move goes beyond matching keywords in the email and the ad. Greater relevancy means tapping into signals based on emails opened or moved to the Priority Inbox or marked as important. Users should see fewer -- yet more relevent -- ads.

The ads will join the conversation by relying on the same technology built into Priority Inbox, which helps predict the importance of the topic in the email. Only some U.S. users will see this feature initially, as Google continues to test and tweak the feature.

For instance, someone who recently read many messages about attending MediaPost's Search Insider Summit in Captiva, Florida in May might want to see offers from airlines with special fares to nearby airports. Those who marked these types of messages as unimportant may not want to see the offer. The plan is to show fewer ads overall and focus on more useful subjects.

It's not clear whether the feature will influence Gmail on tablets, such as iPad 2, Motorola Xoom, or BlackBerry Playbook.

Google does not support ads attached to Gmail through smartphones, such as BlackBerry, but mobile continues to push email as a valuable marketing tool. The majority of emails, however, are still opened on a desktop or laptop computer. In fact, eMarketer points to estimates from Knotice, which reveal that 86.64% of recipients open emails on a desktop: 70.27% on machines running Windows operating systems, 16.19% on Mac, and 0.18% on Linux.

The email open rate on mobile includes iPhone, 8.74%; iPad, 2.00%; Android, 1.92%; Windows, 0.31%; Palm, 0.25%; and BlackBerry, 0.15%, according to the Knotice "Mobile Email Opens Report" published January 2011.

Google is also experimenting with new types of ads, such as local offers and coupons. In June 2010, Google previewed maps and got directions from within Gmail and Buzz. It occurs whenever a user receives an address or a Google Maps link in an email. No emails are read by staffers to protect user privacy, but technology does scan the content for keywords that might match those advertisers bid on.

Separately, Google said Wednesday that it reached an agreement with the U.S. Federal Trade Commission to address privacy concerns. Apologizing for the privacy mistakes made in Buzz, Google said in a blog post that it will receive an independent review of privacy procedures once every two years, and will ask users to provide affirmative consent before changing how it shares their personal information.