If you remember nothing else, remember this: Your CAC (Total Marketing Cost / Total New Customers) is worthless without knowing your CLV ((T x AOV) * AGM) * ALM. Aim for a CLV:CAC ratio of roughly 3:1 ...

It's likely you're measuring ROI for other efforts ... social media updates, or other marketing materials, including those in print? If so, calculate the cost and value of those uses, as well, to ...