The Internet search giant is changing its terms of service starting Nov. 11.
Your reviews of restaurants, shops and products, as well as songs and other content bought on the Google Play store could show up in ads that are displayed to your friends, connections and the broader public when they search on Google. The company calls that feature "shared endorsements."
Google laid out an example of how this could happen: "Katya Klinova," her face and five-star review appear underneath an ad for Summertime Spas.
You can opt out of sharing your reviews.
Google said Friday that the name and photo you use in its social network, Google Plus, is the one that would appear in the ad. Google has said the social network has 390 million active users per month.
"We want to give you and your friends and connections the most useful information. Recommendations from people you know can really help," the company said in an explanation of the changes.
The Mountain View, Calif., company already had a similar setting for its "+1" button, which it introduced in 2011. It had experimented temporarily with putting "+1" endorsements with users' identities in ads, but it hasn't had them up recently. The company said Friday that the choice a user made about allowing for "+1" endorsements would be the default setting for shared endorsements.
Also, if a user chooses to limit an endorsement to certain circles of friends or contacts, that restriction will be respected in any ads that use the endorsement.
Google's move follows a similar proposal by Facebook. The social network in August said it would show users' faces and names in ads about products they clicked to "like." That proposal was criticized by privacy groups. They asked the Federal Trade Commission to look into the matter, which the agency said it did as part of routine monitoring of privacy practices.