I’m currently struggling a little bit with different social metrics. There’s no consensus out there on what is best.
Some say Facebook engagement rate should be measured as (likes+comments+shares)/(page fans) (often referred as page engagement rate) others say it should be measured as (likes+comments+shares)/(page reach) aka post engagement rate. EDIT: Actually I don't know what that approach is called but Post engagement rate is something different again.
Personally I think post engagement rate is better. It doesn’t get skewed by the number of posts (page engagement rates go up the more posts you have because it doesn’t factor post numbers in. You can then divide it over number of posts but it just starts getting weird). Also I don’t think that fan numbers are as important anymore now on Facebook because Facebook is dialing down organic reach so dramatically anyway.
But then you also need to think about whether or not you want to includes clicks in engagements. Tricky!
Then on top of that when you have actually decided on how to measure your engagement rate you then have the issue of communicating it to a client. Because clients usually think there’s only one way of doing it. Then if you've chosen a better but less popular measuring system, you will have a hard time finding industry benchmarks. Total clusterfuck.
Taking a step back
I think the underlying issue is also that we are only just starting to get to the point where we say “Hold on why are we evening measuring any form of engagement in the first place?”. Facebook had a lot of people believing that engagements were a great proxie for share of voice and a great way to get people to buy things. They had it packaged up as “stories” the more “brand stories” your users are telling the more likely their friends are to buy your stuff.
Well that seems a bit shaky now and I do sort of role my eyes at the term “stories” when it pops up on my spreadsheet. Beowulf… The Godfather, those are stories. Clicking like on a brand post… Not a story.
I think engagements are still a nice proxy for excitement. If something excites or arouses people they will probably like and share it. That then implies we've created impactful communications. Which in turn are more likely to stick in peoples’ minds. Add reach to that high quality content and you have a good basis.
An experiment I’d like to do
I’d still like to see how clicks to site and engagement correlate. Or any CTAs and engagement for that matter. Just plot them all out on an X and Y axis and do a regression analysis.