Cost per donor acquired changes every fundraising decision

Aug 29
3 min read

Updated: 3 days ago

Introduction

Fundraising is nearly always judged on the total raised. The event brought in eleven thousand, the appeal brought in four, so the event was the bigger success.

That comparison ignores what each cost to produce, and once you include it the ranking frequently reverses. Cost per donor acquired is an unglamorous number that quietly reorganises where a small charity should spend its limited time, and very few organisations calculate it.

1. Cost per donor acquired requires counting staff time

The omission that invalidates most informal calculations.

Hours spent planning, writing, selling, phoning and running the activity are the largest cost in most small-charity fundraising. Left out, every activity looks cheap, the comparison between them becomes meaningless, and the labour-heavy options appear to be the best value.

2. Count new donors, not total donors

The distinction that makes the number useful.

An appeal to your existing list is not acquisition. Separate the people who had never given before from those who gave again, because the question is what it costs to find somebody new, and a warm list will otherwise make every channel look far more efficient than it is.

3. Calculate it per channel, not overall

An organisational average tells you nothing actionable.

Work it out separately for events, digital, community fundraising, direct mail and face-to-face. The spread between channels is usually wide, and that spread is the whole point of the exercise.

4. Accept that acquisition often loses money at first

This is normal and it is why the number needs context.

Many channels cost more to acquire a donor than that donor gives initially. That is only a problem if they never give again, which is why acquisition cost has to be read alongside retention.

5. Compare it against what the donor is worth over time

The comparison that produces a decision.

Estimate what a typical donor from that channel gives across several years, including whether any of them convert to regular giving. A higher acquisition cost is entirely justified if those donors stay much longer, and a cheap channel producing people who never return is the more expensive option.

6. Look at donor quality, not just quantity

Channels differ in who they bring.

A route producing many small one-off gifts from people who never return is worse than one producing fewer donors who remain for years. Track second-gift rates by source and the picture usually shifts again.

7. Include the cost of the things that failed

Honest accounting includes the misses.

The appeal that flopped, the event that was cancelled, the campaign that produced nothing. Charging these only to the successes flatters every channel and hides that some are far riskier than others.

8. Use it to decide where to stop

The hardest and most valuable application.

Some activities persist because they are traditional rather than because they work. A clear cost per donor, presented to trustees, makes discontinuing something a reasoned decision rather than an admission of failure.

9. Recalculate annually

Costs and returns both move.

Platform fees change, postage rises, digital costs fluctuate and audiences shift. A calculation done once becomes folklore within a couple of years and starts justifying decisions that the current numbers would not support.

Keep the workings, not just the answer. When somebody challenges the figure a year later, being able to show what was counted and how prevents the whole exercise being dismissed and repeated from scratch.

Conclusion

Calculate what it costs to acquire a donor including staff time, because gross raised conceals which fundraising actually works.

Count only genuinely new donors, work it out separately for each channel rather than as an average, expect acquisition to lose money initially and read it alongside retention, compare it against what a donor from that source is worth over several years, track second-gift rates so you judge quality as well as volume, include the campaigns that failed, use the figure to decide what to stop doing, and recalculate every year while keeping the workings.