said 9 months, 3 weeks ago:
Google can’t crawl Facebook posts like they can Google+ posts so they do show up faster in search results. As far as them ranking higher, freshness matters but only for so long (obviously). You need people to engage with the posts you make. Your posts get refreshed in a sense when people engage with them.
You won’t get an SEO boost to your website for posting on Google+. The content on your blog/website needs to be +1′d so it’s important to have your social buttons visible. Asking people to +1 your content on Google+ or after a post is a good idea and can always help!