Quick answer: The mistakes that cost the most are describing the product to yourself instead of the buyer, listing features without the benefit, using the manufacturer’s copy, writing for everyone, ignoring the objection that stops the sale, and formatting a wall of text for desktop when most shoppers are on a phone. Several popular “mistakes” are actually myths worth unlearning, chasing a keyword density, fearing a duplicate content penalty, and padding to a word count, none of which reflect how ranking or buying actually works.
Most product pages do not fail loudly. They quietly convert a little worse than they should, and the store never knows why, because each mistake feels small. Put together, they are the difference between a page that sells and one shoppers skim and leave. This is the closing spoke of our ecommerce copywriting guide, and it collects the mistakes worth fixing, including a few that most advice gets backwards.
Writing to yourself, not the buyer
The most common mistake is copy that describes the product from the seller’s point of view (“we are proud to present,” “crafted with care”) instead of the buyer’s (“stays cold from morning to your evening workout”). Buyers do not care what you are proud of; they care what the product does for them. Every line should answer the buyer’s silent “what’s in it for me,” which is the whole method in how to write product descriptions that convert.
Listing features without benefits
A spec dump is not a description. “304 stainless steel, 500ml, double-wall” tells a buyer facts but gives them no reason to want it. The fix is not to delete the specs but to translate them into what they do for the buyer, and keep the spec as proof, the balance covered in features versus benefits. Features without benefits is the most widespread copy failure in ecommerce.
Using the manufacturer’s copy
Supplier descriptions are written for resellers, generic, and duplicated across every competitor selling the same item. They fail to convert and leave you invisible in search, filtered out behind the version Google chose to rank. Rewriting them from your buyer’s angle is one of the highest-return jobs a store can do, and it is covered in rewriting manufacturer descriptions.
Writing for everyone
“Perfect for anyone” appeals to no one. Copy that tries to speak to every possible buyer speaks to none of them, because nobody feels it was written for them. Pick the one buyer each product is really for and write to them specifically. Specificity is what makes a shopper recognize themselves in the copy.
Ignoring the objection
Every product has a “yeah, but” moment, the hesitation that ends the visit. Not answering it (the sizing worry, the compatibility question, the price doubt) is a silently lost sale. The objections you should answer are sitting in your reviews and support inbox, and handling them is closely tied to your product page trust signals.
Formatting for desktop, not mobile
Most shoppers are on a phone, scanning. A dense wall of text, no paragraph breaks, no bullets, the deciding information buried three paragraphs down, loses them before they reach the point. Lead with what matters, keep paragraphs short, use bullets for benefits, and preview every description on a phone before publishing.
Vague, unprovable claims
“Premium quality.” “Unparalleled comfort.” “The best you can buy.” These superlatives are invisible to buyers because everyone uses them and none can be verified. Replace every vague claim with a specific: not “long-lasting,” but “still going strong after five years, according to buyers.” Concrete detail persuades; superlatives are noise.
Shipping AI copy unedited
AI is a useful drafting tool, but publishing its output unread invites generic phrasing, filler words (“elevate,” “unlock,” “seamless”), and, worst, hallucinated specs that cause returns. The fix is not to avoid AI but to edit it: ground it in real data and check every draft for accuracy and voice, as covered in AI product descriptions.
The myths worth unlearning
Some widely repeated “rules” are mistakes in themselves, and following them wastes effort or does harm. In the interest of accuracy, here are the ones to drop:
Chasing a keyword density. There is no ideal keyword density, and Google does not use one. Writing to hit a percentage produces worse copy that ranks no better. Use your keyword naturally and move on.
Fearing a duplicate content penalty. There is no duplicate content penalty. Google consolidates duplicates and ranks one version, so supplier copy leaves you filtered out, not punished. The fix is differentiation, never hiding pages with noindex, which only removes you from search entirely.
Padding to a word count. Word count is not a ranking factor, and padding to reach one can hurt under Google’s helpful-content system. Write enough to answer the buyer and justify the price, no more, which is covered in how much copy a product page needs.
Adding FAQ schema for rich results. Google removed FAQ rich results from search in May 2026. FAQ content still helps buyers and AI, but the schema no longer earns a SERP feature, so do not add it expecting one.
Unlearning these frees you to spend effort on what actually moves rankings and sales: useful, specific, buyer-focused copy.
Common mistakes (at a glance)
- Seller-focused copy. Write the buyer’s outcome, not your pride.
- Spec dumps. Translate features into benefits; keep specs as proof.
- Supplier descriptions. Generic and duplicated; rewrite them.
- Writing for everyone. Pick one buyer per product.
- Unanswered objections. Handle the “yeah, but” on the page.
- Desktop formatting. Short, scannable, mobile-first.
- Vague superlatives. Replace with specifics buyers can believe.
- Unedited AI. Ground it, check it, give it your voice.
Frequently asked questions
Why do my product descriptions not convert? Usually because they describe the product from the seller’s view, list features without benefits, use generic or supplier copy, try to appeal to everyone, or fail to answer the objection that stops the sale, often formatted as a wall of text on mobile. Fixing those, and writing for one specific buyer, is what turns a description from filler into a selling tool.
Is using the manufacturer’s product description really a mistake? Yes, on two fronts. It is written for resellers rather than your buyers, so it does not persuade, and it is duplicated across every store selling the item, so Google filters you out behind the version it chose to rank. Rewriting supplier copy from your buyer’s angle is one of the highest-impact fixes available.
Does keyword density matter for product descriptions? No. Google has said there is no ideal keyword density, and writing to hit a percentage produces worse copy without ranking benefit. Use your primary keyword naturally a few times and focus on writing for the buyer; that serves both conversion and search.
Will duplicate descriptions get my store penalized? There is no duplicate content penalty. Google consolidates identical content and ranks one version, leaving duplicates filtered out rather than punished. The fix is to make your copy genuinely distinct, not to hide pages, and never noindex product pages to “avoid a penalty,” which removes them from search entirely.
How long should a product description be to avoid mistakes? There is no ideal length; word count is not a ranking factor. Write enough to answer the buyer’s questions and objections and justify the price, then stop. Padding to hit a number can hurt, and starving a complex product of detail loses the sale. Completeness, not length, is the target.
None of these mistakes is dramatic on its own, which is exactly why they persist, each one costs a little, invisibly, on every product page. Fix them together and the effect compounds: copy written for the buyer, features turned into reasons, objections answered, specifics instead of superlatives, and effort spent on what actually works rather than on myths. That is the difference between a catalog of pages shoppers skim and leave, and one that quietly sells, product after product.
Want your product pages audited for the mistakes costing you sales, and rewritten to convert? Ecommerce product copywriting does exactly that, or book a free audit to find the leaks in your catalog.
About the author
Mustajab Haider Bukhari is the founder of Organic Cart Studio, an ecommerce SEO and conversion agency specializing in Shopify and WooCommerce stores. He works hands-on across conversion copywriting, product page optimization, and SEO for online stores. Connect on LinkedIn.
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