TL;DR
Usually not, and the standard advice to rewrite all of them is why so many catalogues never get anything done. There is no duplicate content penalty. You just cannot win a comparison you never entered. Rewrite ten to thirty, not three thousand, and never paraphrase what the manufacturer already wrote.
Usually not, and the standard advice to rewrite all of them is the reason so many catalogues never get anything done.
Here is the actual answer: rewrite the ones that can rank, leave the rest, and delete the ones that should not exist. Which is a different job from rewriting three thousand product pages, and a job somebody can start on Monday.
What the duplication actually costs
Less than people think, and not what they think.
There is no penalty for using a supplied description. Google does not punish it. What happens is quieter: your page is one of several hundred containing the identical text, so it has nothing to distinguish it, and Google picks whichever of those pages it considers most trustworthy. That is usually the manufacturer or the largest retailer, and it is not you.
So the cost is not a penalty. It is that you cannot win a comparison you have not entered.
And it is a crowded field by construction. HTTP Archive’s 2025 Web Almanac found ecommerce software on 19.2% of mobile sites. A very large number of stores are listing the same items with the same supplied text, and being the four-hundredth copy is not a position improved by paraphrasing.
Where the “add 500 words” advice goes wrong
I have written a version of it myself in older audits and I would write it differently now.
It is not wrong so much as unactionable, and unactionable advice does real damage. The owner hears three thousand descriptions, concludes it is impossible, and does nothing at all. So the twenty pages that could genuinely have ranked stay untouched, and the template fix that would have helped all three thousand never happens either.
Note also what Google’s spam policies say about content produced at scale: the definition of scaled content abuse turns on pages “generated for the primary purpose of manipulating search rankings and not helping users”, and contains no word count anywhere. Three thousand paraphrased descriptions written to hit a length are closer to that definition than to a solution.
Which ones to rewrite
The same filter I would apply to any product page. Does anybody search for this specific item. Can you say something the manufacturer cannot. Will it still be on sale in six months. Would you back it with internal links.
On most catalogues that is ten to thirty products, not three thousand. Thin at scale is rarely a writing problem. It is a decision nobody made about which pages deserve the effort.
What to write, when you do
Not a paraphrase. Paraphrasing is the worst possible use of the time. It costs as much as writing and adds nothing a customer wants.
What a retailer can say that a manufacturer cannot:
- Fit and comparison. How it compares to the other three you stock. Which one you would recommend and for whom. The manufacturer cannot write that sentence.
- What you have learned from selling it. What gets returned and why. What people ask before buying. Which size runs small.
- Practical specifics. Whether it fits the thing customers actually want it for. Photographs of the real item rather than the supplied render.
Two honest paragraphs of that beat eight hundred words of restatement, and it is content nobody can copy because it comes from handling the stock.
What the other 2,970 need
Keep the supplied description. It is accurate and customers do read it.
Add the template-level baseline that costs nothing per product: a unique title, a real H1, correct structured data, alt text, and a breadcrumb linking up to a category that is a ranking project. One change, whole catalogue.
Then accept that those pages exist to convert people who arrive, not to attract them. That is a legitimate job for a page.
The short version
- There is no duplicate content penalty. You just cannot win a comparison you have not entered.
- 19.2% of mobile sites are ecommerce, and the same text is on hundreds of stores.
- “Rewrite everything” is unactionable, so nothing gets done at all.
- Google’s scaled content definition has no word count in it.
- Rewrite ten to thirty, not three thousand.
- Never paraphrase. Write fit, comparison and what you learned from selling it.
- Everything else gets the template baseline and converts rather than attracts.
If a site should be ranking and it isn’t, that’s the work I do. Ecommerce SEO covers catalogues, categories and what to write where. If you’re not sure which of several plausible problems is costing you, that’s what an SEO audit is for.
