The Virality of LinkedIn Endorsements

Granted, this is a high-level breakdown of the virality of LinkedIn Endorsements, but still somewhat interesting. Would be much better if there was actual data showing the virality and engagement on LinkedIn, but no dice.

Some people love this feature and some people hate this feature. I think both work well with LinkedIn in that all people talk about it and some people use it a bunch. I don't really see a ton of value in that it's just a +1 for certain skills, so easily manipulated versus a written recommendation they offer, but if well-respected endorse you, that can definitely help. Thoughts?