Google +1 button helps people "vote" for your site or to be specific, pages of your site. Google has not given out the word about how are they using Google +1 recommendation is Search results. However, we are sure that they do make some difference in search results.
I had my old blog which I had to abandon for some reason (How I failed at blogging initially?). I used to click Google +1 for all of my blog post on that blog. When I tried to search Google for "Remainder Theorem" which was the title of my one of the blog post, I was surprised to see it was at first page of Google Search. Note that I was logged in to my account and I could see "You shared this" below that search result. See the screenshot below:
Later I logged out from my account and made the same search again. I could not find that post in first hundred pages even. So Google uses +1 to display results when you are logged in.Of course they might be using it when you are not logged in. But it directly impacts your search if you are logged in.
If I +1 some post about topic ABC and I search for it again while I am logged in, I am surely going to see that +1ed result in the search driving me again to that page and helping that site to retail visitors.
I would love to here your opinions about +1. So mind sharing some thoughts?
