I suspect that deep down inside, if given the choice most letting and estate agents would ditch the whole social media thing and just go for the kill because the social media and engaging with potential clients is hard and takes too much time. We live in a society with a mindset of wanting (and nearly getting) everything "right now".
Technology has made gathering or sending information extremely fast and we've begun to think that everything in life should be available on demand. We are always ready for instant gratification and if we don't have to be patient, we as human beings wont be... and that includes us agents.
.. but you know as in life and relationships .. anything worth having require time, persistence and bucket loads of patience.