So I've been talked down off the ledge and am led to believe that perhaps ALL my efforts to disabuse the Marketing and Advertising nabobs of their obsession with counting eyeballs are not in vain, when there are so many more important things that you can and should measure. One more time – who CARES how many eyeballs you reach if they don't do anything with the information you send them? They all seem to have the direct mail disease that seems to think that it's great if 90% of your effort is wasted.
But here's another take on it. Let's assume that your internal data says that reaching eyeballs really does lead to sales or market share or something meaningful to your bottom line. And lets assume that your competition can draw the same conclusion. Presumably the most important metric, therefore would be your share of the social media conversation. (SOC). Forget about the actual number of eyeballs – what really matters is that you get more than the other guys, right?
Now obviously you only care about certain conversations that matter – and regardless of how you define "matter" no one can argue that there are different levels of authority/influence/rankings depending on what industry you're in. So if you define the universe of conversation of which you need to be a part, based on ranking, authority, or personal preference, your share of that conversation (can we call it BRP Blog Rating Points?) would be a key metric. And, while it might not have a monetary value like a Gross Rating Point, GRP) since most of the cost to reach that universe is undefined or free, it pretty quickly tells you how you're doing in the marketplace. And, if you must to put a dollar figure on it, rather than look at CPM, look at a cost per SOC – i.e. what did it cost you to purchase 1 percentage share of that universe. Take the total cost of your social media marketing program and divide it by your share of discussion.
The formula looks like this: CSoC = Social Media Budget / SOC where CSoC (Cost per Share of Discussion) is equal to the total Social Media Budget divided by your Share of Discussion.
So if you spent $100,000 and your share of discussion in your marketplace was 25% your CSoC would be $4. Which would be great unless of course the competition also spent $100,000 and got 50% share of discussion. It's CSoC would then be $2.