This +1 Button is the key to check website’s popularity for Google. If you want to get actual benefit, you will have to get clicked as fast as possible. But It should be correct form.
First search your website through keyword. If it is ranking on 4th or 5th page, let it ranked over there. Say to your friend to search keyword and go to your website through search engine only and then click on +1 Button. It will help you to get desired result.
If anyone click on this+1 button without reaching your website through search engine, you will not get advantage of this feature.
+1 button enables your visibility on higher ranking only for people who have clicked on +1 or in the network of person who is clicking +1.