To evaluate an e-commerce agency case study, look past the headline result. Check the starting point, measurement period, spend level, attribution method, and work the agency actually performed. Then ask whether the example is relevant to your business.
A big percentage can get your attention. It should also start a conversation. “ROAS increased 25%” tells you something useful, but it does not tell you the starting ROAS, the brand’s margins, or whether the result is likely to carry over to your store.
1. Start with the problem, not the percentage
Was the brand struggling with tracking, creative fatigue, a weak offer, inconsistent campaigns, or an inability to scale? A case study is more useful when it shows that the agency understood the constraint before changing the account.
Look for a connection between the diagnosis and the work. If tracking was unreliable, what changed before the team started making budget decisions? If creative was the bottleneck, what new ideas were tested?
Be cautious when the entire explanation is “we optimized.” You want enough detail to understand the agency’s judgment.
2. Ask what the result is being compared with
A 25% increase is a relative change, not an absolute result. For example, increasing ROAS from 2.0 to 2.5 is a 25% improvement. Increasing it from 4.0 to 5.0 is also a 25% improvement. Those outcomes can mean very different things for a business.
Ask for the starting value, the end value, the comparison dates, and any major promotions or seasonal differences. If the client cannot share exact figures publicly, ask what context can be discussed privately.
3. Read spend and efficiency together
Maintaining efficiency while spending substantially more is a different achievement from improving efficiency after cutting most of the budget. Neither is automatically the wrong decision. They solve different problems.
Best Practice Media’s Drip EZ case study reports a 430% increase in ad spend alongside a 25% improvement in ROAS, a 43% increase in click-through rate, and a 15% reduction in cost per purchase. Those paired measures give more context than the ROAS improvement alone.
The public page does not specify the comparison dates or attribution window. A buyer should ask about those before treating the figures as a forecast.
4. Check which metric actually improved
- Click-through rate: Did more people click? That is useful creative feedback, but it does not establish profitability.
- Cost per purchase: Did acquisition become less expensive under the stated measurement method?
- ROAS: How much revenue was attributed relative to media spend?
- Contribution or profit: What remained after the relevant costs?
- New-customer growth: Did the business acquire more first-time buyers, or mainly reach returning customers?
Do not let a click metric quietly stand in for a business outcome. Ask how the reported metric connects with what you need the engagement to achieve.
5. Separate documented facts from assumptions
Our Cacao case study reports a 34% ROAS improvement while spend increased by more than 100%. It describes creative work around a premium gifting product and purchase-focused optimization.
That supports a discussion about relevant experience with luxury e-commerce. It does not establish the client’s net profit, prove that one specific creative change caused the entire result, or promise the same outcome for another brand.
A credible agency should be comfortable making those distinctions about its own work.
6. Look for a relevant challenge, not an identical product
An agency does not need a case study for your exact product to be a fit. Similar economics and constraints can be more useful than a matching category.
Consider average order value, repeat-purchase behavior, sales cycle, creative requirements, budget, seasonality, and inventory. A team that understands premium gifting may have relevant experience for another considered purchase, even if the product is different.
Ask: “Which parts of this approach would carry over to us, and which would you change?” The answer reveals more than a familiar logo.
A short checklist for the sales call
- What were the baseline, dates, and spend levels?
- Which data source and attribution settings produced the results?
- What did the agency do, and what did the client or other partners do?
- What did not work, and how did the plan change?
- Which details are not available in the public case study?
- Why is this engagement relevant to our business?
Use case studies as evidence to investigate, not a substitute for that conversation. For a broader evaluation framework, read how to choose a paid social agency for e-commerce. You can also explore Best Practice Media’s paid social services to see how the work is structured.