The Internet search leader has been using "+1" recommendation button on its own site for two months. It became available to other publishers Wednesday.
The +1 feature is similar to the Facebook "Like" button that has become a staple at thousands of websites.
Pressing the +1 or Like button enables people to recommend an article, photo, video, song or some other kind of material to their online connections.
The personal endorsement also says something about an individual's interests and preferences. That's something both Google Inc. and Facebook want to know more about so they can do a better job placing the online ads that generate most of their revenue.
