By the time a brand is on Shopify Plus, the constraint has usually stopped being budget. It is measurement. You are running paid social, paid search, email, SMS, affiliate, and probably a marketplace, every platform is claiming credit for the same orders, and the sum of your channel-reported revenue exceeds what actually landed in the bank. Somewhere in that gap is the answer to which channel is genuinely incremental, and most brands at this stage cannot see it.
That changes what you should be hiring for. At $500k in revenue, the right agency is whoever can find more profitable demand. At Shopify Plus scale, the right agency is whoever can tell you which of your existing spend is buying orders you would have received anyway, and then reallocate against that answer. Those are different skill sets, and plenty of agencies that were excellent at the first are not equipped for the second.
The platform layer matters too, more than most agencies acknowledge. Shopify Plus gives you Functions, Checkout Extensibility, B2B, and Markets, and each one changes what your data layer looks like. An agency that cannot work with your developers on server-side tracking, or that treats the feed as somebody else's problem, will cap your growth regardless of how good its media buying is.
We publish this list and rank ourselves first. Judge the reasoning rather than the position. The methodology is below, and every claim about the four other agencies links to their own site.
What actually separates a good shopify plus agency from a bad one
- Incrementality testing, not just better attribution modeling
- Attribution modeling reallocates credit for orders that already happened. Incrementality testing (geo holdouts, matched-market tests, conversion lift studies) answers the harder question of what would have happened if you had not spent. At Shopify Plus volume you finally have enough data for these tests to be statistically meaningful, and an agency that does not run them is guessing with a more sophisticated dashboard. Ask for a specific example of a test they ran and what they changed as a result.
- Whether they can actually work with your developers
- Server-side tracking, Checkout Extensibility, custom Functions, and a clean product feed all require someone who can hold a technical conversation with your engineering team or your Plus partner agency. Many media agencies cannot, and it becomes your job to translate. Ask who on their team writes the tracking spec, and ask to talk to that person before you sign.
- Contribution margin as the reporting default
- ROAS ignores COGS, shipping, payment processing, returns, and discounting, all of which are large and highly variable at scale. A brand can grow ROAS while contribution margin falls, particularly if discounting is doing the work. Ask whether the agency's standard reporting includes margin, and whether they are willing to be measured on it. Many will say yes in a pitch and revert to ROAS once the engagement starts.
- Whether strategy and execution are the same people
- At enterprise scale, the common failure mode is a strong pitch team followed by a junior execution team, with channel work split across specialists who never talk to each other. Ask who is in your account weekly, how many other accounts they carry, and who is accountable when paid social and paid search disagree about the same conversion.