, Retail
Your best month came from one marketplace. So did the worst week, three months later, when orders halved on a Tuesday. There was no email, no warning, and no route to an explanation beyond a support queue that answers with a template.
That is the trade every platform seller makes. The platform brings demand you could not have generated and takes a position between you and the person who bought from you.
Commission is not the expensive part
The headline number is the referral fee. Depending on the marketplace and the category, that is commonly between 8% and 15% of the sale price, sometimes more for specialist categories.
The fees that follow are where the margin goes. Fulfilment charges per unit. Storage charged by volume, with long-term surcharges on anything that sits. Advertising, which begins as optional and becomes effectively compulsory the moment competitors bid on the same search, because organic placement gets pushed below the fold. Then returns, which on most platforms operate on the customer's terms rather than yours.
Work out your all-in platform cost as a percentage of sale price, not just the referral fee. Sellers who do this for the first time usually find the real number is half again as high as the one they had in their head, and that a category they thought was profitable is running at a contribution of a few percent once advertising is counted in.
The customer is not yours
The deeper cost is structural. In most marketplace arrangements, the platform holds the customer relationship. You may not get an email address you can use. You are usually restricted from directing buyers to your own site. Reviews attach to the listing, not to you. If you leave, none of it comes with you.
That means every sale builds the platform's asset rather than yours. It also means the platform can, entirely within its terms, change how buyers find you, launch its own version of your best product using data about what sells, or change the fee schedule with notice you have no ability to refuse.
Nothing about that is unlawful. It is the deal. The mistake is treating it as a partnership when it is a tenancy, and a tenancy with a rent review the landlord conducts alone.
The ranking change that halves your week
Search ranking on a marketplace is a black box with public folklore around it. Things that appear to move it include price competitiveness, conversion rate, delivery speed, stock availability, review score and account health metrics.
Two practical implications. First, going out of stock is more expensive than it looks, because you lose position as well as the sales, and regaining position takes longer than restocking. Second, account health metrics, late dispatch, defect rates, cancellation rates, are worth managing to a standard well above the threshold, because the penalty for crossing one is not proportionate to the amount by which you crossed it.
Keep your own record of daily orders, sessions and conversion by listing, exported regularly. When something changes, the only argument you can make is a factual one, and platforms do not keep the history in a form you can use.
Diversify before you have to
The right time to build a second channel is while the first one is working, because that is when you can afford it and when you are least motivated to.
What diversification actually looks like, in rough order of difficulty:
- A second marketplace, which is the easiest and least useful, because it swaps one landlord for two.
- Your own site, fed by the same product data, with the traffic coming from search, email and existing customers rather than from paid acquisition alone.
- Trade or wholesale, where a handful of accounts replace thousands of individual transactions and the relationship is contractual.
- Physical retail, concessions or markets, which are slow and expensive and produce customers no algorithm can take away.
Use the platform for what it is genuinely good at while you do it. It is a customer acquisition channel with a high cost and a very large audience. Insert something in the parcel that gives the buyer a reason to come to you directly next time, within the platform's rules, which usually permit a straightforward brand insert while prohibiting anything that reads as diverting the sale.
The regulation that may or may not help
The Competition and Markets Authority gained new powers under the Digital Markets, Competition and Consumers Act 2024 to designate firms as having strategic market status in a digital activity and to impose conduct requirements on them, including on fair dealing and on the use of data. The CMA began opening investigations under the regime during 2025.
Whether that reaches the specific thing that halved your week is not something to plan around. Treat it as background weather. The regime is worth following, and it is not a substitute for having somewhere else to sell.
The one regulation that does bite immediately is on your own conduct as a seller. The consumer protection provisions of the same Act, in force from April 2025, cover fake reviews and drip pricing, and platforms enforce their own versions aggressively because they are exposed too.
Where this shows up in the game
E-commerce is one of the five business types in Business Baron's free game, so you can run an online shop at no cost. Marketing is campaigns with a channel mix, and the attribution tells you less than you would like about which channel is carrying you. Building your own route to the customer is slower, and it is what stops a bad quarter becoming the end of the company.