Email ROI Math: How Many Sales Pay for Done‑For‑You Email?
Fast takeaway: You don’t need a massive list to afford expert, done‑for‑you email. In most cases, a handful of incremental orders per month covers the cost—and everything after that is margin.
Why This Guide
If you’re like most founders and lean marketing teams we talk to, you know email should be doing more. You’ve got a list, maybe a welcome email, and the occasional promo blast—but not the automated, revenue‑pulling engine you see from bigger brands. The blocker? Budget (and time to manage yet another vendor).
This post gives you a dead‑simple way to answer the one question that matters: “How many sales does it take to pay for someone else to run email for us?”
We’ll walk through:
A 5‑input ROI calculator you can run in 60 seconds.
Break‑even examples for common ecommerce and service models.
Why automations (welcome, abandon cart, post‑purchase) usually pay for themselves before campaigns even ship.
How Milhook’s Full‑Service vs Pay‑Per‑Email pricing fits different budgets.
A downloadable Google Sheet you can copy and plug your numbers into.
The 60‑Second Break‑Even Formula
You only need five numbers:
Service Cost / Month (what you’d pay Milhook or another provider)
Average Order Value (AOV)
Gross Margin %
Incremental Conversion Count you think email can add per month (or per campaign cycle)
Attribution % (how much of the order value you’re willing to credit to email—100% for email‑only offers; lower if email assists)
Formula:
Incremental Profit from Email = Incremental Conversions × AOV × Gross Margin × Attribution %
Break-Even Conversions = Service Cost / (AOV × Gross Margin × Attribution %)If your expected incremental conversions ≥ break‑even conversions, done‑for‑you email pays for itself.
Worked Example #1 – Small Shopify Brand
Scenario: You sell $50 average‑price consumables with 60% gross margin. You’re evaluating a $1,000/mo done‑for‑you email service.
Break‑Even Conversions:
= $1,000 / ($50 × 0.60 × 1.0) = 33.3 orders → 34 ordersIf Milhook helps you drive 34 incremental orders in a month, your service is covered. Everything after that is contribution profit.
What 34 orders looks like:
5 recovered abandoned carts per week = ~20/mo
Welcome series converting 2% of 700 new subs/mo = 14 orders
You’re already at 34 without sending a single promo blast.
Worked Example #2 – Higher‑Ticket DTC (AOV $150)
Service: $1,500/mo. Margin: 55%.
Break‑Even:
= $1,500 / ($150 × 0.55 × 1.0) ≈ 18.2 → 19 ordersNineteen incremental orders covers the whole month. A single targeted product spotlight to lapsed buyers + abandoned checkout automation can do that.
Worked Example #3 – B2B / Services Paid Leads → Conversions Later
When revenue isn’t tied to immediate checkout, swap in Lead Value (avg closed‑deal revenue × close rate).
Example:
Avg closed project = $12,000
Close rate on qualified leads = 25%
Lead Value = $12,000 × 0.25 = $3,000
Gross Margin on services (after delivery cost) = 40%
Milhook retainer = $2,000/mo
Break‑Even Leads:
= $2,000 / ($3,000 × 0.40) = 1.67 → 2 incremental qualified leads / monthTwo real leads from email pays for the month.
What Counts as “Incremental” Revenue?
This trips people up. You don’t need to prove beyond a shadow of a doubt that email caused the purchase—you need a defensible model your finance lead will accept.
Common attribution approaches:
Last Click: If the order came from an email click, give email 100%.
Click‑Assist Window: Count email‑clicked buyers who converted within X days (often 5–7) at 100% or fractional credit.
View‑Through: Email opened but buyer converted organically—give 20–50% assist credit.
Automation‑Only: For triggered flows (abandon cart, welcome), attribute 100% of first purchase if no other paid touch in the path.
Pick one method, stick with it, and compare month over month.
Where Incremental Orders Come From (In Order of ROI Speed)
Below are the automation + campaign building blocks that most often pay for the service quickly—especially for under‑resourced teams.
1. Welcome / First‑Purchase Flow
Captures new subscribers while intent is high. Include offer, top sellers, social proof. Even a 1‑3% first‑purchase conversion on new signups can cover a big chunk of cost.
2. Abandoned Cart / Checkout Rescue
Usually the fastest revenue win. Pulls back 5–15% of would‑be lost carts when properly timed and incentivized.
3. Post‑Purchase (Cross‑Sell / Replenish)
Drive 2nd order velocity—huge LTV lever. Even a small uplift in repeat rate compounds monthly.
4. Winback / Lapsed Buyer
Re‑engage past buyers with targeted offer or new collection highlight.
5. Lite Monthly Campaign Cadence
1–2 branded sends to segments (new, repeat, VIP, seasonal) keep list warm and seed future automation performance.
Estimating Conversion Lift (Benchmarks Cheat Sheet)
Below are directional ranges marketers use when modeling ROI. Plug in the conservative end if you’re nervous; the math still works.
Flow / TacticConservative Revenue Impact RangeNotesWelcome Flow$0.50–$3.00 per new subscriber in first 30 daysOffer + top product block drives quick wins.Abandoned CartRecovers 5–15% of abandoned revenueMulti‑step w/ reminder + incentive performs best.Post‑Purchase Cross‑Sell+5–20% increase in repeat order rateTriggered by product or time‑to‑reorder.Winback1–5% reactivation of 90‑180 day lapsedDepends on offer strength + seasonality.Campaign Lift0.5–2% of targeted segment convertingHighly variable; segment quality matters.
(Use your own data if you have it; these are modeling aids.)
Plug‑In ROI Mini Calculator (Copy/Paste)
Paste into a spreadsheet and fill the yellow cells.
Metric,Input,Notes,Formula
Monthly Service Cost,1000,Your fee to Milhook or provider,
Average Order Value (AOV),50,Avg $ per order,
Gross Margin %,0.60,As decimal (0.60=60%),
Attribution %,1.00,1.00=100% credit to email,
Break-Even Conversions,,,"=A2/(A3*A4*A5)"How Milhook Pricing Fits the Math
We keep pricing flexible so smaller brands can ramp up without over‑committing.
Option A – Full‑Service Monthly
We build and manage automations + 1–4 campaigns/mo. Best if you want a full revenue engine.
Option B – Pay‑Per‑Email
Perfect for brands testing email or filling internal gaps. You pay only for the sends you need (design + copy + build).
When Pay‑Per‑Email Wins: Seasonal bursts, product launches, sale events, one‑off nurture. When Full‑Service Wins: You want ongoing growth, segmentation, testing, and reporting.
What If My List Is Small?
Small lists convert too—especially with automations that fire off behavior (signup, cart, purchase). Even 5–10 new orders from a welcome offer + a few cart recoveries can materially offset a starter plan.
If your list is <5,000 contacts, start with:
Welcome / First‑Purchase Flow
Abandoned Cart
One simple monthly campaign Run 60 days, compare revenue vs service cost—then scale.
ROI Red Flags (Watch These Before You Sign Any Email Contract)
No revenue attribution plan. If the vendor can’t show revenue tied to sends, pass.
Locked into long contracts. 12‑month minimums before value = risk.
Design‑only shops. Pretty emails that don’t segment or automate = low ROI.
No A/B testing cadence. Without testing, performance plateaus.
Milhook runs month‑to‑month, reports on attributed revenue, and launches core money‑flows first so you see impact fast.
Implementation Timeline (Example 30‑Day Sprint)
Week 0–1: Data + access, list hygiene, creative intake. Week 1–2: Welcome & Abandon Cart live. Week 2–3: Post‑Purchase + first campaign. Week 3–4: Reporting, optimization, next flows.
Break‑even checkpoint at Day 45: Compare incremental revenue to service cost.
FAQ: Quick Hits
Do I need fancy segmentation? Not at first—new vs returning buyers + cart abandoners covers 80% of early ROI.
What platforms do you support? Klaviyo, Mailchimp, HubSpot, Omnisend, Drip, and more.
How do I track revenue? Use native platform attribution + UTM tags + your ecommerce dashboard for validation.
Ready to See Your Numbers?
Grab the editable calculator and plug in your data. If you’d like us to review it with you and build a right‑sized plan, book a quick call.
