Gorkana - the very useful media database people - have published an interesting free to download white paper on public relations in 2016. 

It discusses the blurring of boundaries between the traditional marketing and PR teams, and how agencies have had to adapt and change.

Ownership of social media is at the heart of this, the paper argues, with uncertainty over who owns it.  Is it a comms function or a marketing function or both?

Digital has not meant the death of the traditional PR function, and nor will it.  Content remains at the heart of good comms campaigns, whether in print or on digital channels. 

And PR should not just mean media relations - it is vital that a good PR understands how all the parts fit into a client's strategy, and what works best and when.