Every development team has the same folder. Call it "lapsed" — donors who gave once, maybe twice, and then went quiet. Eighteen months without a gift. They're not gone, exactly. They just stopped opening your email.
The instinct is to email them harder. A five-touch reactivation series, one message every few days, each one a little more urgent than the last. It costs almost nothing to send, so why not? Because "almost nothing" is only true on the sending side. The real cost is what a fifth ignored email does to whether they ever open a sixth.
Full disclosure: I work for Ready, an SMS platform. So I have a bias toward the text-message answer here. I'll show you the math so you can check my work instead of taking my word for it.
What a five-email reactivation series actually costs
Email feels free. It isn't quite. But the per-send cost is genuinely tiny — most nonprofit ESPs price on list size, so a lapsed segment of 5,000 contacts costs you a few dollars of your monthly plan, spread across all five touches. Round it to zero.
The cost that matters is different. Every email to a disengaged contact drags down your sender reputation. Mailbox providers watch open rates, spam complaints, and deletes-without-opens. Send five emails in two weeks to someone who's ignored you for a year and a half, and you're teaching Gmail that your mail belongs in Promotions — or Spam — for everyone on your list, not just the lapsed ones.
So the honest cost of the five-email series is:
- Near-zero cash
- Real deliverability erosion across your whole file
- A meaningful chance the donor mentally files you under "the org that won't stop emailing me"
You can send it. It just doesn't move much, and it can quietly cost you inbox placement you'll want for your year-end appeal.
What one text costs, to the penny
An SMS to that same lapsed donor is one segment if you keep it under 160 characters. At Ready's Standard tier that's $0.02 per segment plus the $0.0045 carrier pass-through — $0.0245 all-in.
Here's a re-permission message that fits in one segment:
Hi Maria, it's the Riverside Food Bank. We miss you. Reply YES to keep getting updates by text, or STOP to opt out. Msg&data rates may apply.
That's 143 characters. One segment. Two and a half cents.
For a lapsed file of 5,000 donors:
| Channel | Per-contact cost | 5,000 contacts | Reputation risk |
|---|---|---|---|
| One SMS re-permission | $0.0245 | $122.50 | Isolated to SMS opt-outs |
| Five-email series | ~$0 marginal | ~$0 | Whole-file deliverability |
The text costs $122.50 you can see on a Stripe invoice. The email costs nothing you can see — and something you can't.
The response gap is where the money is
Opted-in SMS lists tend to respond in a range email can't touch. I'll frame these as rough industry approximations, not guarantees: opted-in text campaigns often see response rates around 30–50%, versus low-single-digit open-to-click on cold, lapsed email.
Say your re-permission text lands a 20% re-opt-in from a lapsed file — conservative, because these people liked you enough to give once. That's 1,000 donors back on a channel they'll actually read. If a follow-up appeal to those 1,000 recovers even 8% at an average reactivation gift of $40:
- 1,000 re-opted-in × 8% = 80 gifts
- 80 × $40 = $3,200 raised
Total SMS cost so far: $122.50 for the re-permission blast, plus another ~$25 for the appeal to the 1,000 who opted back in (1,000 × $0.0245). Call it $147.50 to raise $3,200.
That's about $0.046 spent per dollar raised — under a nickel. Your direct-mail reactivation package doesn't come close. And nobody's file reputation took a hit.
The email series, meanwhile, might recover a handful of gifts from the fraction who still open you. It's not zero. It's just not $3,200, and it's carrying a hidden deliverability tax.
Aged consent is the part everyone skips
Here's where I have to slow you down, because the math above only works if you can legally send that first text.
A phone number sitting in your donor CRM is not consent to text. If someone gave you a mobile number on a paper pledge card in 2021, that's a phone number — not an SMS opt-in. Texting them a marketing or fundraising message without express written consent is exactly the exposure the TCPA is built to punish, and the penalties run $500 to $1,500 per message. On a 5,000-contact blast, that's not a rounding error.
Consent doesn't expire on a clean clock, but it does go stale in practice. Numbers get reassigned. People forget they ever gave you a mobile. Aged donor lists are the highest-risk lists to text cold, precisely because the consent record is usually thin or nonexistent.
Two things protect you:
- Scrub before you send. Run the file against known TCPA-litigator and DNC-complainer lists first. Ready's standalone scrub is $0.005 per contact — 5,000 numbers is $25 to suppress the people most likely to turn a marginal-consent text into a five-figure claim. We wrote about why the timing matters: scrubbing after import is too late.
- Treat the first text as a re-permission, not an appeal. Don't ask for money in message one. Ask for permission to keep texting. That reframes the send and builds a fresh, dated opt-in record for everyone who replies YES.
If you're not confident you have real SMS consent on this file, the safe path isn't "text them anyway." It's to re-permission through a channel you are cleared on — including email — and collect a proper opt-in going forward. Which brings us to the checkbox.
Getting consent right going forward
The fix for aged consent is to stop creating aged consent. Every donation form and event signup should capture SMS opt-in explicitly — not a pre-checked box, not "phone number" buried in the shipping fields. A clear, separate checkbox with the required disclosure language.
We broke this down in detail in adding a phone field isn't consent to text. The short version: the opt-in language has to say what they're agreeing to, from whom, at what frequency, with STOP and message-rate disclosures. Get that in place and the donor you acquire today never becomes the compliance headache you're re-permissioning in eighteen months.
Ready records that opt-in attestation on bulk and API sends, so you're building an audit trail as you go — which is the thing you'll wish you had if a number ever gets disputed.
The compliance stack that makes this safe to run at scale
Reactivation blasts are exactly the kind of send where the details bite you. A few things worth having handled automatically rather than by hand:
- Automatic STOP handling. When a lapsed donor replies STOP, they're suppressed — and it propagates so they don't get pulled back into the next campaign. Opt-out that actually sticks across sends.
- Quiet-hours enforcement. A reactivation text that lands at 11pm local time reads as spam and raises TCPA exposure. Sends are held to permitted local hours by the recipient's area.
- Litigator / DNC scrubbing at $0.005/contact, as above.
- 10DLC registration handled in-app — brand (~$10/mo) and campaign (~$20/mo), approval usually 1–3 days. Unregistered fundraising traffic gets carrier-filtered, so this isn't optional if you want the message to arrive.
None of this makes you lawsuit-proof — compliance is ultimately your organization's responsibility, and no vendor can promise otherwise. It reduces the surface area of things that go wrong on an aged file, which is the whole game with lapsed-donor sends.
The practical takeaway
Reactivating a lapsed donor by text is cheap — a couple of cents per contact — but the cost was never the point. The point is that a five-email series to people who've ignored you for a year and a half spends something you can't itemize: your deliverability and your standing with a donor who used to care.
One well-worded re-permission text, sent to a scrubbed list from a registered number, does two things a fifth email can't. It reaches people where they actually read. And it rebuilds a clean, dated consent record you'll be glad to have at year-end.
If you want to size this against your own lapsed file, the fastest way is to start small — pull your last 500 lapsed donors, confirm your consent situation, and run one re-permission send. Ready gives you 2,500 free credits to start, no card required, which covers a test that size with room to spare. You can see the product and pricing here or sign up and try the math on real numbers instead of mine.