How to Choose an Ecommerce Email Marketing Agency

Hiring an ecommerce email marketing agency should give you a clear path to more profitable customer relationships. Before you commit, you should understand the opportunity in your account, the work included in the fee, who will do it, and how you will judge the results.

Start by comparing agencies on five things: their diagnosis of your account, the economics of their proposal, their execution team, their measurement approach, and your ownership of the work.

My experience building and selling an ecommerce brand shapes how I think about this decision. When you are responsible for inventory, payroll, and customer acquisition, a marketing expense has to make sense within the whole business. That is the perspective behind Ecom Growers, and the standard I would use when hiring an agency myself.

Start with the improvement your business needs

Give prospective agencies a specific problem to investigate.

You might have a steady stream of first orders but few customers returning for a second purchase. Your signup form might attract subscribers who rarely buy. You might have useful products to explain but no one with time to turn that information into consistent campaigns.

Those situations call for different work.

For a product customers replenish, the opportunity could involve identifying the usual reorder window and testing reminders around it. For a durable product, it could involve education, complementary products, or a new launch. Sending both audiences the same sequence would ignore how they buy.

Write down the outcome you want, your current performance, and the operational constraints the agency needs to understand. Include stock availability, margins, upcoming launches, and the time your team can spend approving content.

Calculate what the agency needs to earn back

Before comparing proposals, estimate the additional sales needed to cover the added cost.

Additional net sales needed to break even = added monthly program cost ÷ contribution margin

Contribution margin is the percentage of net sales remaining after variable costs such as products, fulfillment, shipping subsidies, and payment fees. Use sales after discounts and refunds, and include the variable costs relevant to your business.

Consider this hypothetical example. These figures are illustrative, not Ecom Growers pricing.

• Added monthly cost versus your current setup: $4,500
• Contribution margin before that added cost: 45%
• Additional monthly net sales needed to break even: $10,000
• Average net sales per additional order: $100
• Additional orders needed at that order value: 100

This gives you a useful starting point for the conversation. An agency should be able to explain where the opportunity for those additional orders might exist and what assumptions would need to hold.

Include setup fees, extra software or messaging charges, and the internal work you will still need to do. If you are replacing an existing agency, compare the change in cost and expected performance against the program you already have.

Clearing the break-even point covers the added expense. Your investment should also have a credible path to producing profit beyond it.

Understand the revenue an agency is claiming

Email-attributed revenue measures sales credited to email under a platform’s attribution rules. Incremental revenue estimates the extra sales your marketing caused compared with what would have happened without it.

That distinction matters when your account already generates orders.

Klaviyo explains that attribution depends on eligible interactions and configured time windows. A sale receiving email credit does not, by itself, establish that the customer would otherwise have never purchased.

Consider a hypothetical store where total monthly sales fall from $500,000 to $400,000 while attributed email sales stay at $100,000. Email’s share rises from 20% to 25%, even though its attributed sales have not increased.

Ask the agency to agree on a baseline and report attributed revenue alongside total store performance, repeat purchasing, discounts, and program costs. Record the attribution settings used for comparisons.

Where the audience and test design support it, a randomized holdout can help estimate marketing’s incremental impact by comparing customers who receive messages with a comparable group who do not. Klaviyo’s built-in global holdout feature currently requires at least 400,000 total profiles, so it will not suit every account.

Smaller accounts still deserve clear reporting. Changes in traffic, offers, inventory, and seasonality should be discussed alongside the results, with uncertainty explained honestly.

Review the work inside the proposal

An ecommerce email marketing agency may handle strategy, copywriting, design, campaigns, automated flows, signup forms, segmentation, testing, and reporting. Some also manage SMS. Your contract should identify the responsibilities you are actually buying.

Request a scope that covers:

• Campaigns: Planning, writing, design, audience selection, scheduling, quality checks, and the approval process.
• Automated flows: Which existing flows will be reviewed, which will be rebuilt, and how future testing and maintenance are handled.
• Subscriber growth: Responsibility for signup forms, offer testing, and evaluating whether new subscribers become customers.
• Deliverability: Monitoring, account configuration reviews, list management, and responsibility for investigating problems.
• Reporting: The measures, comparison periods, meeting schedule, and decisions each report should support.
• SMS: Whether it is included, how messages coordinate with email, and how messaging costs are handled.

A campaign count helps you understand production capacity. Pair that number with the strategy and maintenance work behind it.

For example, a purchase recovery flow needs more than attractive emails. The team should examine when customers enter, when they should exit, whether purchasers are excluded appropriately, and how messages interact with other offers.

Ask for evidence that matches your starting point

A case study is more useful when you understand the conditions behind the result.

Request the starting performance, the dates, the work completed, and the definition of the reported revenue. Discuss changes in paid traffic, promotions, list size, inventory, or product launches during the same period.

A store with no functioning purchase recovery emails has a different opportunity from a mature brand that has tested them for years. The first result should not become the second brand’s forecast.

You can also ask to see examples of the agency’s thinking: a redacted testing plan, a campaign brief, a flow map, or a sample monthly report. These help you assess how the team makes decisions without requiring another client’s confidential data.

Meet the person who will own your account. Understand who handles strategy, who builds and checks the messages, and how questions or urgent changes reach the right person.

Put ownership and working expectations in writing

Your brand should retain control of its marketing account and customer data. The agreement should clearly explain access to the templates, copy, designs, and other work you pay for, including any separately licensed assets.

Set expectations for approvals, revisions, response times, minimum commitments, cancellation, and handover. If your team takes several days to approve a campaign, build that into the schedule before a launch becomes urgent.

Coordination also matters when different partners handle acquisition and retention. Decide who shares the promotional calendar, customer insights, landing page offers, and stock changes. A specialist email team can work alongside a paid media agency when those responsibilities are clear.

Agree on the first 90 days

Use the first 90 days as a planning framework, with the schedule adjusted to the work your account needs.

Days 1–30: Establish access and reporting definitions, review the customer journey, prioritize fixes, and agree on the campaign and testing calendar. Address urgent problems and begin the highest-priority work as approvals allow.

Days 31–60: Launch the agreed improvements, check that they work correctly, and collect enough data to evaluate the first tests. Document what changed and why.

Days 61–90: Review results against the baseline, account for changes elsewhere in the business, and decide what to expand, revise, or stop.

This is a delivery framework. Revenue timelines depend on your audience, buying cycle, starting condition, and the changes being tested.

Use this checklist during agency calls

Mark each item confirmed, unclear, or missing. Keep the supporting evidence beside it so you can compare proposals after the calls.

• Opportunity: Account-specific findings and a prioritized plan
• Economics: Full program costs and the assumptions behind expected improvement
• Measurement: Baseline, attribution settings, and sample reporting
• Execution: Named account lead, responsibilities, and relevant work examples
• Delivery: Written scope, approval process, and first 90 days
• Ownership: Account control, asset rights, and handover terms

Apply the same checklist to every agency, including Ecom Growers. You should be able to explain your choice in terms of the work your business needs and the evidence you have seen.

Common decisions when hiring an email agency

Agency fees and what they include

Compare written proposals for the same scope. Separate recurring fees from setup work, platform charges, SMS usage, and services billed separately. The break-even calculation above helps connect each proposal to your own economics without relying on a generic industry price.

A freelancer or an agency

A skilled freelancer can be a good fit for a defined project or an ongoing workload within their capacity. An agency can make sense when you need several disciplines and coordinated delivery. An internal hire can provide close day-to-day ownership. Evaluate the actual people and responsibilities in each option.

Choosing a Klaviyo agency

If your store uses Klaviyo, ask the agency to demonstrate practical experience inside the platform: integrations, flow logic, segmentation, deliverability, testing, and reporting. Have them explain a specific account problem and how they would investigate it.

Hiring before the business is ready

A substantial ongoing retainer can be difficult to justify when you have very little traffic, few subscribers, or inconsistent demand. A focused setup project or limited specialist engagement may better match the opportunity while you build the customer base.

Evaluate your email program with Ecom Growers

Ecom Growers builds email and SMS programs for ecommerce brands, with a focus on Shopify businesses doing $3 million to $30 million in annual revenue.

Our email revenue audit is a starting point for reviewing your current performance, identifying gaps, and discussing a plan for improvement. Bring your goals, your current costs, and the areas you want to understand better.

Book your email revenue audit with Ecom Growers.