How to Calculate (and Improve) Your Email Marketing ROI
Cost per send in email marketing is low enough that many businesses never seriously calculate ROI at all — the assumption is that if it's cheap, it must be paying off. Open rates and click rates get watched instead, because they're easy to see in a dashboard. Neither one tells you whether email is actually making money, and that gap is where a lot of avoidable underperformance hides.
Why open rate and click rate aren't ROI
Open rate and click rate measure engagement, not outcome. A campaign can post a strong open rate and still generate no revenue, and a campaign with a modest open rate can quietly drive most of a month's sales. Treating engagement metrics as a proxy for ROI leads to optimizing for the wrong thing — chasing opens with clickbait subject lines rather than chasing the revenue an email actually produces.
Engagement metrics can mislead
A subject line optimized purely to maximize opens can pull in curiosity clicks from people with no intent to buy, inflating engagement numbers while doing nothing for revenue.
The actual ROI formula
Email marketing ROI, in its simplest useful form, is revenue attributed to email minus the cost of running email marketing, divided by that cost.
The formula
ROI = (Revenue attributed to email − Cost of email marketing) ÷ Cost of email marketing
How to calculate it properly
Total your email marketing cost
Platform subscription, design or copywriting time, and any list-growth spend. This is usually the easy half of the equation.
Attribute revenue to email, not just to the store overall
Use tracked links and order attribution so a purchase within a defined window of an email click is credited to that campaign, rather than lumping all revenue into 'organic' or 'direct'.
Separate one-off campaign revenue from automation revenue
Automated flows like abandoned cart or welcome sequences often generate steady revenue that a single-campaign view misses entirely — track them as their own line.
Calculate ROI per campaign type, not just overall
An overall ROI figure can hide the fact that broadcast newsletters barely break even while automated flows carry most of the return.
Revenue attribution is the part most businesses skip
Attribution requires connecting an email click to an eventual order, which means tracked links, a consistent attribution window, and ideally a platform that ties email activity to the same contact record as your orders. Without it, you're left estimating email's contribution to revenue rather than measuring it, which makes it hard to defend the budget or know where to invest more.
Practical ways to improve ROI
Where the improvements usually come from
“A low cost per send doesn't guarantee a high return. It just means the return is easy to waste without anyone noticing.”
Where Havari fits into ROI tracking
Because Havari keeps email, SMS and WhatsApp activity against the same contact record, revenue attribution doesn't have to stop at email — a sale that started with an email click and closed after an SMS reminder still gets tracked back to the sequence that drove it, rather than disappearing into a generic 'direct' revenue bucket.
What attribution window should I use?
There's no universal answer, but a short window (a few days) suits impulse purchases while a longer one (a couple of weeks) suits considered purchases. Pick a window that matches your typical buying cycle and apply it consistently so figures are comparable over time.
Should I include list-cleaning time as a cost?
It's worth including if it's a regular, deliberate task, since it directly affects deliverability and therefore revenue. For most businesses it's a small cost relative to the return it protects.
Is a positive ROI enough, or should I compare it to other channels?
Compare it. Email's low cost per send often means its ROI figure looks strong in isolation, but the more useful question is whether that budget and attention would produce more return moved to automation, segmentation, or another channel entirely.
Email marketing ROI isn't something a low cost per send guarantees on its own — it's something you calculate, by tracking revenue back to the campaigns and automations that actually produced it, and then acting on what that attribution shows you.