It's worth taking another look at the recent Gartner presentation on "Adjust Selling to 2019’s Buying Realities".  One slide that stood out for me was that only 17% of the total time spent on key buying activities was meeting with suppliers. 

Whereas 27% of the time is spent researching independently.  This presents a great opportunity for the salesperson to seize a comparatively larger proportion of this time through their social presence.

The salesperson doesn't need to be constrained by the time set by the client in a meeting near the end of the process. They now have an almost limitless opportunity to provide engaging, fact-based content that will help prospective clients on their buying journey

Furthermore, we know that 1% of users post content on Linkedin, but over 80% of potential buyers use it for research purposes.  Why miss this opportunity to engage earlier, rather than sitting back and being a small part of the 17%?