None of 'em would take a bullet for you! Some would make a hashtag. All will talk about how much they miss you on their profiles. Sometimes, that's enough for me.
In my own personal order of worst to first on what I expect my online friends to do for me: LinkedIn, Pinterest, Twitter, Instagram and Facebook. I only have three friends on Facebook. The chart was made by Ted McCagg. [Ted McCagg via Laughing Squid]