Return on investment (ROI) is a performance measure that allows you to determine the success of a campaign. To calculate ROI you need to divide the return of a campaign by the cost.
Return on Investment is key to any business, as you need to make sure your campaigns are profitable enough for you to continue spending on them.
It is important to remember that as members sign up to subscription packages you may not see a positive ROI in the first month.
For example, if a member signs up and continues to re-bill for 6 months, the life-time value will not be known in month one and therefore it may appear that you're experiencing a loss until the member's start to re-bill.
To calculate ROI you need to divide the return of a campaign by the cost. You can then multiply this by 100 to get a percentage.