There was an interesting discussion related to this sometime back on Google Groups. https://productforums.google.com/forum/#!msg/webmasters/pX0sI1KOnTM/60MmAnGN5fsJ

The conclusion I would say is that you can link from the client websites, but make sure you do not stuff keywords in the anchor text. As long as someone is linking with the brand name, it shouldn't have any issues.

If you want to share your blogpost content on Facebook then the best way is to share it via updates or add the link to the notes. You can also rewrite the summary of the blogpost and add a catchy text so that people click the link to go to your blog.

For e.g. Latest trends show that............ To read more on this, click....