Data about the success of your post: how to understand that mess

There is a relatively new data point regarding the success of your post that I like:

It is called Members reached. Now I need you to understand the connection between the newly available data and numbers that were always available:

Impressions = how many times someone saw your posts. Even for a second, he might have just scrolled it over. Or has actually read it for a minute? You do not see the quality of impressions, just the number.

Unless you look at the context of other data...

Members reached =?a number of unique people who saw your post. Still, we do not know how long they have watched. But in this specific example, we know that 2 855 - 1 757 = 1 098. I have watched your post twice. Or, to be more precise, a little bit less, but some of them saw it even more than two times.

Now, in case you published a video, we get even better data here:

Video views = out of 2 855 impressions, we have 1 196 views (42% conversion).

Lifetime unique viewers = out of 1 757 unique members reached 1 099 decided to watch the video (63% conversion, which is actually great feedback, since most often this number is somewhere between 20 and 40%).

And my favorite data:

Now, this particular video had 77 seconds. People have watched it for 392 minutes. That means that the average person saw 21 seconds, which is 28% of the video length.

So, was this particular post a success? No. It had a nice catch that made people start watching the video. But on average, people watch over 30% of the length of the relevant videos. So, this video lost their interest pretty quickly. Hence next time I need to make it more relevant to them, but I may try to use this kind of catch again.