A great look at the impact of Google +1 and it effect on
Small Business Marketing and SEO
The idea behind +1 is a simple one. In search results, and later directly on websites, searchers will be able to up-vote search results they like. These sites will be bookmarked on your profile page. When the same site appears in the search results of a friend, a tag will appear underneath the snippet indicating that you liked it. Google will show you +1's from your contacts in Gmail, Buzz, and Google Reader.