20 A/B Testing Ideas for Fundraising Appeal Letters

It Takes More Than Gut Instinct to Acquire and Retain Donors

Looking for A/B testing ideas for fundraising appeal letters that actually move the needle?

Healthcare, education and nonprofit fundraisers like you face unique challenges — whether your donors are patients grateful for their caregivers, passionate alumni wanting to help more students access education or folks inspired to make an impact within their community. Raising funds through your appeal letters or annual fund shouldn’t be one of them.

That’s where testing comes in.

Without testing the appeal letter tactics that motivate your donors to give or continue to support your cause, you’re basically crossing your fingers and hoping for the best (hey, we’ve all been there!) Strategic testing turns your fundraising from educated guesswork into a science experiment with actual results you can take to the bank — or better yet, to your mission.

Let’s dive into some tests worth trying!

1. Personal Story vs. Statistics

One beneficiary’s journey or thousands served? Industry research shows that individual stories (whether it’s a patient testimonial or a profile of someone helped by your organization) typically generate stronger emotional connections than statistics alone. But are your constituents motivated more by cold, hard numbers?

2. Emergency vs. Opportunity

“We must act now” or “Together, we can transform the future?” Different donor segments may respond differently to urgency versus vision-based messaging. This test could be ideal for time-specific events, like a capital campaign with a firm deadline or National Doctors’ Day for example.

3. Ask Placement

Front vs. back of letter; opening sentence vs. closer to the end. Testing where your donation request appears can help you create more strategic messaging in the future. You could also test the number of asks throughout the letter.

4. Problem-Solution vs. Vision 

Are your donors motivated by fixing immediate problems or creating lasting legacies? Are they compelled by a more emotional story of a child that’s hungry or a brighter view of a future where all children are nourished to flourish. This single test can reshape your entire messaging approach.

5. Gift Ask Amounts

Does your audience respond best to standard giving increments or suggested ask amounts based on their previous giving history? You can even use variable data to test their propensity to give more.

6. Matching Gift Offers

According to Double the Donation, matching gift offers may help increase both response rates and average gifts. 1 in 3 donors even say they’d give a larger gift if matching is applied to their donation. Do special incentives like matching gifts or double the donation campaigns work well with your donors?

7. Photo Subjects

Technical/program photos vs. candid moments of real people. Stock photos or pictures of actual students, staff or patients? Images showing emotional connections might perform better in your appeals, no matter whether you’re raising funds for your hospital, food bank, arts or other nonprofit organization. But can the same be said for yours?

8. Letter Length

Short and sweet or more detailed storytelling? Contrary to what you might expect, longer letters can sometimes perform well when the story is compelling. You’ll never know if a short letter performs better for your audience unless you test.

9. Envelope Teaser

To tease or not to tease? This A/B testing idea for your fundraising appeal letters can provide insight into whether preview messaging increases your open rates, an important metric for any campaign.

10. Giving History Personalization

A very specific message like “your past support helped provide [specific impact]” vs. a more general “Your support matters.” Using variable data, you can even incorporate the amount the donor gave in the past to a specific cause or test general images vs. those specific to a program the donor has already supported.

11. Program Segmentation

Appeals based on known interests (like cardiology or cancer care) or general support for the organization as a whole? Industry best practices suggest that aligning communications with demonstrated interests can often improve results. Consider testing a story showcasing a student whose education and career flourished after a life-changing, donor-funded scholarship vs. a general ask to support your educational institute.

12. Monthly Giving Emphasis

Test recurring gift focus against one-time requests. Monthly donor programs may yield higher lifetime value for all types of nonprofits, so determine whether including them in all your asks is the way to go.

13. Digital Integration

QR codes/text-to-give vs. traditional reply cards. Sidebars with links to videos and other interactive pieces related to your fundraising campaign or appeal letter story. Online notes of gratitude vs. printed notecards. Test whether your audience responds better to digital response options vs. traditional methods.

14. Restricted vs. Unrestricted Funds 

Do you have a specific project in immediate need of funding support or do you want donors to support the area of greatest need? This varies dramatically by donor segment, but testing reveals your donors’ trust and interest levels regardless of your nonprofit category — and can bring some much-needed resources to certain programs or initiatives within your organization.

15. Johnson Box Text

That summary box at the top of appeals can improve readership for longer messages, especially with older audiences according to nonprofit direct mail insights. Think of sidebar elements to test that help you maximum as much space as possible.

16. Lapsed Donor Reactivation

“We miss you” messaging or “new fundraising opportunity” framing? Different approaches may resonate differently depending on why your donors fell off in the first place. You may be able to regain these supporters if you know how best to appeal to their interests.

17. Paper Quality/Weight

Does premium stock justify its cost? For major donor segments, the perceived value might translate to engagement, though this requires testing with your specific audience. But some mid-level donors may see a more sophisticated appeal and think your organization already has the funding it needs.

18. Imagery

Graphics/illustrations vs. photos of real people. Your visuals are just as important as your message in showcasing your cause’s priorities and the impact donors can have on them. Perhaps consider testing a traditional text-only letter style against one with carefully selected images that reinforce your message.

19. Success Story vs. Ongoing Need

Specific stories of accomplishment and impact or ongoing challenges within your community? Different causes may see different patterns in donor response based on how they frame needs and victories.

20. Letter Signer

Executive Director, Board Chair or program recipient signatures? Patient or provider? Social worker or family supported by services? Testing different letter signers can reveal whose voice carries the most weight with your donors.

Implementing Your A/B Testing Ideas

The real power of these A/B testing ideas for fundraising appeal letters isn’t just in immediate improvements. It’s in the extraordinary knowledge bank you build about your donors over time.

The most successful healthcare, education, and nonprofit fundraisers make testing a standard part of their fundraising strategy. So, which testing idea will your organization try? The more data you have about your donor audience, the more you can improve response rates, donor acquisition and retention, and average gifts year over year.