How does +1 affect search results?

+1 helps people discover relevant content—a website, a Google search result, or an ad—from the people they already know and trust. Adding the +1 button to your pages lets users recommend your content, knowing that their friends and contacts will see their recommendation when it’s most relevant—in the context of Google search results.

When a signed-in Google user is searching, your Google search result snippet may be annotated with the names of the user's connections who've +1'd your page. If none of a user's connections has +1'd your page, your snippet may display the aggregate number of +1's your page has received.