Just because it is expected doesn't make it a good thing and it doesn't mean its not hurting your conversions and rankings.
PageRank is a numeric value that represents how important a page is on the web. Google figures that when one page links to another page, it is effectively casting a vote for the other page. The more votes that are cast for a page, the more important the page must be.
1.) Those links are making Facebook stronger and more powerfull and help Facebook content out rank dealership content.
To calculate the PageRank for a page, all of its inbound links are taken into account. These are links from within the site and links from outside the site.
PR(A) = (1-d) + d(PR(t1)/C(t1) + ... + PR(tn)/C(tn))
That's the equation that calculates a page's PageRank.
It's the original one that was published when PageRank was being developed, and it is probable that Google uses a variation of it but they aren't telling us what it is.
It doesn't matter though, as this equation is good enough.
The juice that flows from the links are divided by all the links on the page.
So the internal links on the site get less linkjuice sorry power, or pagerank because it is being divided my the links that are going to the social media sites.
In addition to this it is an off topic link because every link on the page should be there to help the user have a better experience, and if your talking about oil filters and place a link to send a user to Facebook to show them an add about cars, because you like spending money with Facebook more than making money, that is not a good user experince.
Other words, not having links to social media sites would give you a compeitive advantage over your compeition!
