The most common marketplace mistakes cost you time and money, and most can be avoided. Here are 10 traps we see most often.
Author: Borys Terlecki · marketplace sales and implementations at Commercraft · updated: September 2026
In short
Marketplace sales are rarely sunk by spectacular errors, more often by small, repeatable mistakes that cost visibility, margin and time.
The most common: a shop price carried over without commission and returns, poor product cards, messy EAN codes, no advertising plan and repricing with no floor.
Add to that a single channel, underestimated returns, machine translations for export and formalities (EPR, GPSR, VAT) closed off after the fact.
The most common reasons why selling on a marketplace does not take off are rarely spectacular. They are usually small, repeatable mistakes that cost visibility, margin and nerves. The good news: almost all of them can be fixed. We have gathered the ten most common ones, from experience with hundreds of sellers and platforms.
A price carried over from your shop to a marketplace without accounting for commission, the cost of returns and advertising can produce sales without profit. The starting point is the real take rate, not the price tag from your online shop.
One weak photo, a description focused on features instead of benefits, and empty attributes are a recipe for low conversion and high returns. The product card is your only salesperson, so it is worth letting it speak in full voice.
Duplicates, missing codes, one EAN across many variants: this is one of the most common reasons offers get rejected. Clean data is a condition of entry, not an add-on.
On many platforms, without advertising a new product is practically invisible. Listing an offer and waiting is not a strategy: campaigns need to be planned and their profitability watched.
Ratings and response time affect not only customer decisions but also an offer’s position. Ignored questions and unhandled reviews are a real sales cost.
Repricing without a set minimum price pulls you into a spiral of discounts that destroys your margin. Automation is great, but only with a hard price floor.
Basing all your sales on a single platform is a risk: a rule change or an account block hits the entire business. Diversifying channels means both safety and growth.
Especially in fashion and in the DACH markets, returns can turn a margin upside down. Left out of the calculation, they turn a seemingly profitable channel into a loss-making one.
Product cards ‘run through a translator’ for German-speaking markets undermine credibility and can fail to meet language requirements. Local, correct content is an advantage on DACH.
Missing EPR numbers, non-compliance with GPSR or disorganized VAT during expansion can block offers overnight. These are areas better closed off before the start than fixed on the fly.
We catch most of these mistakes in an account analysis before they start to cost you, and then we build a strategy for pricing, content, data, advertising and logistics so that sales are healthy and scalable, including in the Poland-DACH corridor. Want to check which of these traps apply to you? Write to us.
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Borys Terlecki – marketplace sales and implementations at Commercraft. He previously worked on the operator side of marketplace platforms (Mirakl, Munich) and today onboards brands on marketplaces in Poland and the DACH region and runs their accounts.
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