A campaign raises $4,000, and the organization celebrates its best month ever. Then someone sits down and honestly does the math: advertising, a contractor's fee, roughly a hundred hours of team time spent preparing and running it.
Raising the money cost more than the money itself. The celebration wasn't about money, it was about the illusion of money: the number on the screen looked like success, while the real arithmetic said the opposite.
Three numbers change how you look at any money-raising channel: cost per donor acquisition, retention, the share of donors who give again a year later, and lifetime value, how much a donor brings in on average over their whole relationship with the organization. A channel gets judged not by how much it raised in one go, but by the ratio of lifetime value to acquisition cost.
Cost per acquisition is all the channel's costs divided by the number of new donors it actually brought in. This includes not just advertising, but a contractor's fee and a reasonable estimate of the team's hours, even if that's volunteer time.
Retention is the share of donors who give again a year after their first gift. Lifetime value is the amount a donor brings in on average over the entire time they stay with the organization, not in a single moment.
A channel with an expensive first gift can turn out to be the best choice, if the donors it brings in stay with the organization for years. An expensive entry point pays for itself through a long relationship history, and that's invisible in the short term but enormous over a horizon of several years.
A recurring donor giving $15 a month is usually worth more than a one-time donor who gave $100 once, simply because their lifetime value eventually outgrows the one-time amount several times over. A retention increase of just a few percentage points often brings in more money than launching a new acquisition campaign: keeping someone you already know is cheaper than convincing a stranger.
A small organization doesn't need corporate-level analytics with dozens of metrics. It needs three numbers for each active channel, calculated quarterly, the same way every time.
Precision down to the last dollar matters less than honesty and consistency in the calculation. The trend, whether retention is rising or falling, whether a channel pays off or not, matters more than the exact decimal in any single quarter.
Below is a calculator for one channel's unit economics. Enter your costs, number of new and repeat donors, and average gift size, and see your cost per acquisition, retention, and lifetime value, with a verdict on the channel.
Your unit economics calculation for each active money-raising channel, or for the plan for the next six months, if you don't have channels yet. Update these numbers quarterly and keep them next to your revenue mix from your revenue mix, they read best together.
What if the organization only has one acquisition channel so far?
That's normal at the start. Calculate the numbers for that one channel specifically: even one honest number beats a feeling of "seems like it's working."
Do I have to include the team's volunteer time in the calculation?
Yes, at least roughly. Otherwise the channel will look cheaper than it actually is, and decisions based on a distorted picture often lead you the wrong way.
What do I do with a channel that lands in the "costs more than it brings in" zone?
It doesn't necessarily need to be shut down right away, sometimes lowering costs or improving donor follow-up after the first gift is enough, see the donor journey. But this zone isn't worth ignoring.
How do I estimate retention if the organization is less than a year old?
Use a conservative estimate based on similar organizations or sector benchmarks, and recalculate the number as soon as you have your own full year of data.
Now you have a numeric language for evaluating any fundraising channel. But all three numbers in this lesson assume the organization already has some channels and some history. A very young organization doesn't have that history yet in year one. The next lesson honestly covers where to actually look for money when there's nothing behind you yet.
The material in this lesson is educational and drafted for review by your attorney and CPA. This course does not replace professional advice and makes no promise of outcomes.