John Gruber, absolutely killing it on share buttons, particularly on Medium:
I love Medium. I don't mean to be overly harsh on Medium, but he's right.
Share buttons — dickbars, in Gruber's parlance — are not only unnecessary, but they're starting to border on user-hostile. They're absolutely one of the worst things about the modern web experience, made a thousand times worse when they're also presented in a modal when the page first loads.
Gotta wonder about the actual savvy of all the marketing/design groups telling clients to do this. If your goal is to boost engagement this way, you're spending too much time on things that aren't the content.