With social media measurement, sometimes simple is best. There are automated tools like Sparkwise and SumAll that will pull metrics in from various websites and track change over time, but I believe half of the magic of measurement is the practice. Numbers alone don’t tell a complete story–you need to take notes about the content or events that cause spikes or drops in engagement so you can refine your approach over time. And that’s why I go low-tech with a very simple Excel spreadsheet.
You can download it here.