That said, I've never clicked on a share button mostly because:
- I don't know what it will do, it's not consistent at all
- It might add extra crap "Your friend shared 'Story Title' with you!"
- It will probably try/want to add tracking crap
I always just copy the URL and send it however I want to send it. People aren't stupid when it comes to sharing, they understand how to accomplish what they want, we don't need a dedicated share button.
What we don't have, and hopefully never will, is the number of people who click the share button verses the people that copy/paste the URL which I assume 90% of people who want to share do. It's universal, it "just works".
Clicking the share button means I'm at the mercy of the site operator, copying the URL puts me in control.