We often get asked "which social media metrics should we be tracking?" or "how much is [X metric] worth?" The easy answer is, it depends. The better answer is that the most valuable social metrics, and the ones you should be tracking, are the ones that align with your goals. A lot of times though, the metrics a social network has and the metrics you need are two different things.
When this happens, it may be time to start creating your own metrics in order to measure success.
An easy example is engagement rate. Say you have a goal to become the best-quality social brand in your area of expertise. Basically, you don't want a single fan to go to waste—or at least, you want the most engaged fans as possible. You could measure engagement by totaling up all the social actions on your social pages during a given timeframe. But that still wouldn't tell you the overall quality of your community. If you determine that, "we have 600 engaged fans," what is that really saying? Engagement rate will show you how interested your community really is. Six-hundred engaged fans on a page with 1,200 followers is great—that's a 50 percent engagement rate! Six-hundred engaged fans on a page with 20,000 followers is much less impressive—it's an engagement rate of only 3 percent.
Even within a stat like engagement rate, there are several variables you can use to determine value. Even better, your personalized stats are much more portable than those made up by the big social networks. A Facebook "Like" only exists on Facebook. But something like affinity can live anywhere—a Facebook Like, a Twitter favorite, and so on.
Start with what you want to accomplish: What do you want to do with your social profiles? From there, you can begin to determine what kinds of metrics you'll need to pay attention to, to measure your success.