What actually stays with you on an order, channel by channel
Doing this calculation honestly means including every item, the awkward ones too. Take an order of one thousand euros, net of VAT.
On the traditional channel with an agent at five per cent: fifty euros of commission, plus around four euros of social contributions on your side, plus the accrual for the end of the relationship and the customer indemnity that build on that commission.
Rounded, you are around sixty euros. To which you add the cost of the order itself: whoever takes it, whoever enters it, whoever prepares it.
On a marketplace at seven per cent: seventy euros of commission. Plus the annual fee, which on a single order would weigh heavily but which spreads across every order of the year — at ten orders it is twenty euros each, at a hundred it is two.
On the single order, then, the traditional channel can cost less. That is true and it needs saying.
But the single order is the wrong comparison, and why becomes visible only when you widen the view to the year.
The agent costs on the orders they do not bring, too. The minimum contribution is due regardless, the fund accrues regardless, and time spent in an unproductive area is time paid for.
The marketplace costs nothing on the orders that do not arrive. In a month with no sales, the expense is the annual fee divided by twelve.
Then there is an item nobody counts and which weighs as much as the others: whoever takes the order.
A telephone order occupies a person for some minutes, has to be transcribed, and every transcription is an opportunity for error. An order that arrives already written, with verified billing details and VAT calculated, does not carry that cost.
The real calculation, then, is not made on one order but on a year and a territory: what a channel costs you in total, divided by what actually comes in through it.
Done that way, the comparison stops being five versus seven per cent and becomes two different ways of carrying risk.
In summary: on a single order the traditional channel can cost less, the commission must be grossed up by contributions and accruals, the annual fee spreads across every order of the year, an agent costs even when not selling while a commission does not, and the cost of taking and transcribing the order counts in both cases.