Is there a plugin available that will automatically post an excerpt of a blog post (perhaps up to the more tag) to specified social media groups/pages. So, for example, on posting an excerpt would be posted with a 'Read more' link to a user-defined Facebook group, G+ page and, possibly, twitter feed?
If not, is there a method for automating this process? Or is copy>paste the only realistic option?
(I know that Dsiqus provides the ability to link comments and social media but this functionality doesn't extend to posts, as I understand it.)