Sooo...3yrs later...any change here?
Well, yes and no.
If you're using Marketo's built-in social sharing, you're out of luck--but if you're willing to build your own social link and track that, it's actually pretty straightforward: just use a link structured like
The markup that will display for the share is based on your o:graph tags (which is, incidentally, used by Facebook/LinkedIn as well).
Alternately, you can just use Google's own code and add a little bit of JS to record it.
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