In short
- The first criterion is experience with e-commerce sites: categories, facets, catalogs with thousands of pages.
- A good agency talks about revenue and priorities, not just rankings and content volume.
- Ranges published by agencies themselves put e-commerce support at roughly €750 to over €5,000 per month, depending on catalog size.
- Ask how tag and copy production is organized: this is often where the scope shrinks.
An SEO agency can transform the results of an e-commerce site, or burn through a budget for a year without any effect on sales. The difference rarely comes down to the size of the agency or its prestigious references. It comes down to a few specific criteria.
Criterion 1: experience with e-commerce sites
SEO for an e-commerce site has little to do with SEO for a brochure site or a media site. The core topics are categories, facets, transactional long tail, cannibalization between listing pages, and production at catalog scale. Ask for concrete examples on catalogs of a size comparable to yours, and what the agency did there.
Criterion 2: a method centered on revenue
Listen to the agency's first proposal. Does it talk about your categories and facets, or about an article publishing calendar? That second plan increases traffic, rarely sales, for the reasons detailed in our analysis of e-commerce SEO traffic. A good agency starts by segmenting your traffic by page type and by revenue.
Criterion 3: honest measurement
Monthly reports must track organic non-brand traffic by page type, and the associated revenue. A report that only shows rankings on a list of keywords chosen by the agency does not allow you to judge its work. Google reminds us that no serious provider can guarantee a ranking.
Criterion 4: production organization
This is the question few e-commerce merchants ask, and the most revealing one: who writes the tags and copy for your hundreds of categories and facets, and how?
- by hand by senior consultants: excellent, but the budget will limit the scope to the main pages;
- by hand by junior profiles or external writers: variable quality;
- by automatic templates: fast, but generic;
- by a production tool with quality control, run by the consultants: the full scope, with expert judgment where it matters.
See our article on the agency and automated tools combination.
What budget should you plan for?
There is no official rate card. For example, the agency Optimize 360 publishes e-commerce SEO ranges of €750 to over €3,500 per month for a catalog of fewer than 500 products, and €750 to over €5,000 beyond that. These figures are indicative: above all, compare what is included (audit, technical work, editorial production, links, reporting) and the number of days actually spent on your site.
Warning signs
- Guaranteed rankings: nobody controls Google's algorithm.
- A 100% content plan that ignores your categories.
- An audit with no priorities, delivered as a list of hundreds of items.
- A lack of transparency about what is done each month.
- Links bought in bulk presented as a strategy.
Getting the agency to work on what matters
If you work with an agency, you can suggest it rely on unblind for tag and copy production: it keeps the strategy, sets the parameters (lengths by page type, banned words), validates the results, and spends its time on decisions rather than data entry. You get the full scope, without multiplying billable days.
Frequently asked questions
How much does an e-commerce SEO agency cost?
There is no official reference rate. For example, the agency Optimize 360 publishes ranges of €750 to over €3,500 per month for a site with fewer than 500 products, and €750 to over €5,000 beyond that. The price depends on the scope, the competition and what is included (technical work, content, links).
What are the warning signs with an SEO agency?
Promises of guaranteed rankings, a plan focused on publishing articles without mentioning categories, reports that only measure rankings, or a lack of transparency about what is actually done each month.