When you think about your website’s SEO, you think about Google. Sure, you might do a quick check over at Yahoo and Bing to make sure what you’re doing works there too but let’s face it, your SEO tactics are pretty Google-centric. When you want a new site recognised, you have to tell Google about it. You register the URL with them, invite a bit of googlebot crawling and wait to see the results.
For me, one of the fundamental things to remember about Google+ is that it lets Google know your pages are there.