Most of what an ecommerce SEO agency is hired to do turns out to be an engineering job wearing a marketing job’s clothes. A shop with four thousand products does not have a content problem. It has a URL problem, a duplication problem and a crawl problem, and the reason those persist is that fixing them requires changing the platform rather than writing more copy.
The blogging that usually gets proposed is not wrong, it is just downstream of the thing that is actually suppressing the site. Retailers who reverse that order spend a year producing gift guides while their category pages remain uncrawlable.
The first thing to check on any store: how many URLs your filters generate. A category with six filter dimensions can produce tens of thousands of crawlable combinations from a few hundred products, and search engines will spend their entire budget on near-identical pages instead of the ones you sell from. This is the single most common cause of an ecommerce site that will not rank.
Faceted Navigation, and Why It Quietly Destroys Everything
Filters are good for shoppers and dangerous for crawlers. Every combination of colour, size, brand, price band and sort order can generate its own URL, and each of those looks like a page to a crawler.
The arithmetic gets ugly fast. Six filters with a handful of values each multiply into thousands of combinations per category. Multiply by your category count and a modest catalogue becomes hundreds of thousands of crawlable URLs, almost all of which are near-duplicates of each other and none of which anyone searches for.
The consequences are all indirect, which is why they are missed. Crawl budget is consumed on combinations rather than on new products. Ranking signals are split across variants of the same page. And the index fills with thin pages that dilute the site’s overall quality picture.
The fix is a decision rather than a setting. You choose which filter combinations are genuine landing pages worth ranking, and you make the rest uncrawlable. A colour plus category page is often a real search. A colour plus size plus price plus sort order page never is. Google’s own guidance on managing crawl budget for large sites and on consolidating duplicate URLs is the reference, and any agency proposing work on a large store should be able to talk about both without prompting.
Product Pages, Variants and the Duplication Trap
The second structural problem is variants. If every size and colour has its own URL with the same description, you have manufactured duplication at scale. Consolidating to one canonical product page with selectable variants is usually right, and it is a platform change rather than a content change.
Manufacturer descriptions are the other half of it. If your product copy is the same text the other forty retailers received from the same supplier, there is no reason for a search engine to prefer you. Rewriting four thousand descriptions is not realistic, so the work is prioritised: rewrite the products that already get impressions, and leave the long tail on supplier copy until they earn attention.
Structured data is unusually well supported here. The Product type and Google’s product structured data guidance cover price, availability and reviews, and getting them right is what produces the enhanced results that lift click-through on a listing you already rank for. For a site that ranks reasonably and converts poorly, this is often the cheapest available improvement.
Where an Ecommerce SEO Agency Should Spend Your Budget
Retailers instinctively optimise product pages, because that is where the buying happens. The searches, however, mostly happen a level up. People search for the category and browse to the product.
That makes category pages the pages worth investing in, and they are usually the worst on the site: a heading, a grid, and either no text at all or a block of keyword-stuffed filler pushed below the fold where nobody reads it.
The better pattern is a short, genuinely useful introduction that helps someone choose, placed where a human would actually read it, plus fast-loading imagery. Our guide to WooCommerce catalogue performance covers why grids are usually the slowest pages on a store and what to do about it, and the same arithmetic applies on any platform.
What It Costs in the UK
| Store size | Typical monthly | Focus |
|---|---|---|
| Small catalogue, single market | £800 to £1,800 | Technical fixes, category pages, structured data |
| Mid-market, thousands of SKUs | £2,000 to £4,500 | Faceted navigation, variants, content at scale, digital PR |
| Multi-market or marketplace | £4,500 upwards | Internationalisation, feed quality, governance |
A one-off technical audit is often the better first purchase and runs £1,200 to £2,500 for a small store, £3,000 to £6,000 where facets, variants and internationalisation are involved, and £6,500 to £15,000 or more for large catalogues where server logs and crawl analysis are needed to see what is actually being fetched. Our breakdown of technical SEO audit cost covers what falls into each band.
The log analysis at the top band sounds like a luxury and usually is not. On a large store it is the only way to see that a crawler is spending most of its time on filter combinations, which is the finding that changes the whole plan.
Questions That Separate Specialists From Generalists
Ask how they would handle faceted navigation. A specialist asks how many filters you have before answering. A generalist says they will add canonical tags, which is a partial answer that leaves the crawl waste in place.
Ask what they would do about variant URLs and supplier descriptions. Both answers should involve prioritisation rather than a promise to rewrite everything.
Ask whether they read server logs, and at what catalogue size they would insist on it.
Ask how they would measure success on a store with seasonal demand. Year-on-year comparison is the only sensible frame and an agency reporting month-on-month growth into Christmas is telling you nothing.
Ask what they expect to happen to your indexed page count. On most stores the right answer is that it should fall substantially, and an agency that treats a shrinking index as a failure has misunderstood the problem.
Where to Start
Almost every store we look at has more URLs indexed than products in the catalogue, often by an order of magnitude, and the owner has never been shown that number. It is quick to establish and it reframes the entire budget conversation.
Mecanik runs technical SEO audits that measure crawl waste, duplication and category page performance rather than testing a homepage, and implements the platform changes through our website development team. If your traffic has plateaued while your catalogue has grown, that gap is the reason.
Related reading: Enterprise SEO Agency: Why Large Sites Fail Differently , Medical SEO Agency: What Actually Moves Patient Bookings , Law Firm SEO Agency: Compliance, Content and Cost and Multi-Location SEO for UK Businesses .
Frequently Asked Questions
What is the most common ecommerce SEO problem? Faceted navigation generating vast numbers of crawlable filter combinations. Six filters with a handful of values each can produce thousands of near-identical URLs per category, consuming crawl budget and splitting ranking signals across variants nobody searches for.
Should product variants have their own URLs? Usually not. Separate URLs for each size and colour with identical descriptions manufacture duplication at scale. One canonical product page with selectable variants is generally right, though it is a platform change rather than a content change.
Are category pages or product pages more important for SEO? Category pages, in most cases. Buying happens on product pages but searching mostly happens a level up, and category pages tend to be the weakest on the site: a heading, a grid, and either no text or keyword-stuffed filler below the fold.
How much does an ecommerce SEO agency cost in the UK? A small single-market catalogue typically runs £800 to £1,800 a month, a mid-market store with thousands of SKUs £2,000 to £4,500, and a multi-market or marketplace operation £4,500 upwards. A technical audit runs £1,200 to £2,500 for a small store and up to £15,000 for large catalogues needing log analysis.
Should my indexed page count go down after an SEO project? On most stores, yes, often substantially. Removing crawlable filter combinations and consolidating variants reduces the index to pages that can actually rank. An agency that treats a shrinking index as a failure has misunderstood the problem.
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