A few months ago we released the +1 button on English search ads and organic search results on google.com. More recently, we’ve made the +1 button available to sites across the web, making it easier for people who love your site to help their friends and other users find your content in Google search.

Today, +1s will start appearing on ads and organic search results for Google pages globally. We'll be starting with sites like google.co.uk, google.de, google.co.jp and google.fr, and then expanding quickly to most other Google search sites soon after.

We’ve also partnered with a few more sites in Europe, Japan, India, Australia and New Zealand where you’ll start seeing +1 buttons in the coming days.

You can also add the +1 button to your international websites by going to the +1 button tool on Google Webmaster Central where it's already available in 44 languages.

We expect that personal annotations will help users know when your ads and organic search results are relevant to them, increasing the chances that they'll end up on your site.
Think of +1 buttons as an enhancement that can help already successful search campaigns perform even better, now, at a global level.