I would use Google Plus 1's and Facebook likes, twitter follows etc.. on the page or website you are trying to promote. Each one has its own benefits for ranking in different ways. The Plus 1's are to gauge the importance of a site in Google's eyes so this can directly attribute to your rankings (its still in testing according to Google) but in my own testing sending a large number of Plus 1's (bought) to my webpage I was promoting did help in its rankings imo. If you need help with acquiring these sort of services for traffic to your site then contact me via my profile page...
Google + will help us to get higher SERP. If we get more Google + mean it will gradually increase your serp.