Ask HN: Getting the Facebook share button to work 100%

Facebook is pushing the like button, but for obvious reasons in many cases we prefer the share button.

In doing my research some people have found problems with how the share button scrapes the page so that the wrong metadata is sometimes pulled in.

Does anyone have a concrete description for how to reliably (meaning 100%) get the share button to work?

The core idea is that we want the share button to scrape a specific title and body and allow the user to add a comment. Sometimes the share button scrapes the correct content and sometimes it doesn't.