Quick answer? How much did you spend on clicks? How much did you make? Longer answer? How much did you spend on EVERYTHING THAT WENT INTO THIS (agency/in-house/content/design/development, etc.) and How much did you “net”? Each business is different. Ecommerce calculations are “pretty simple”. B2B? Not so much.
B2B must consider what the conversion rates were into a lead, what the conversion rate of leads were into “qualified leads” and what conversion rate of “qualified leads” were into sales and what the average/real value of those sales were. From there, every business has unique costs (hard costs?) that may need to be subtracted from the calculation in order to determine what “real money” was made from the effort(s).
To help you to determine what it takes to be ROI positive on your PPC efforts, we have developed ROI Marketing Calculators. Please check them out and share your feedback on how we can make them better.