ROI (Return on Investment)

Your ROI is the measure of the profit you make and/or costs saved at your business. For your email marketing campaigns you calculate cost of sending email plus time.

ROI = [(Payback - Investment)/Investment)]*100

So if you made $780 on your email campaign, your time was worth $50 to create it and it costs $15 to send it it would look like this:

(($780 - $65)/$65)*100 = 1100% ROI (which is really good!)

If you want to take it a step further subtract your cost of your products or services as well.