The Maze: Facebook Marketplace lets people list items for sale. Sellers can also pay Facebook to show a listing to more potential buyers. In one test published on 12 October, a seller chose an option that promised an advertising fee only if the item sold. The item was a $50 mousepad. The seller agreed to a fee of up to $10 after a sale. But after the ad started, another Facebook screen showed a $400 daily advertising budget. The test found conflicting instructions. It did not establish that Facebook charged the seller $400.
Source: Meta Business Help Center. This explains how ordinary Facebook ads are charged. It does not establish what the seller paid in this test.
Here is what the seller agreed to. The option was called Cost per Sale. The seller chose to pay Facebook 20% of the item’s price for advertising. On a $50 item, that works out to $10. Facebook’s instructions said this fee would apply if a buyer clicked the advertised listing and bought the item within seven days. The promise was therefore simple: pay an advertising fee when the ad leads to a sale. The fee was for advertising; it should not be confused with shipping costs or any separate selling fees.
Then the screens stopped agreeing. The confirmation screen showed $10. But when the seller opened “Edit boost” in Meta’s advertising tools—Meta is Facebook’s parent company—the settings showed a daily budget of $400. They also said the ad would keep running. An earlier message had said the promotion would end after 30 days or when the item sold out. The seller was now looking at different amounts and different stopping rules for the same ad.
A daily budget and a fee after a sale mean different things. A sale fee answers: “What will this ad cost me if someone buys my item?” A daily budget answers: “How much should the advertising campaign spend per day, on average?” In Meta’s ordinary advertising system, that daily average is calculated over a week. It is not the price of one sale or necessarily a strict limit for each day. So the $400 setting raised a serious question: would Facebook follow the seller’s $10 sale-fee agreement, or could the daily setting affect what the seller paid? The test did not answer that.
The results screen did not settle the billing question. It mainly counted conversations started with potential buyers. A buyer sending a message is not the same as buying the item. Meta’s AI assistant also said the ad was charged each time it appeared on someone’s screen. But an AI answer is not a bill or a verified explanation of this particular ad. The saved results screen showed $0.00 spent for the dates selected. That tells us what the screen showed at that moment; it does not establish the final amount paid.
This is one account test, with important answers still missing. Liz Morton, editor of Value Added Resource, documented the test. Meta had not answered her request for comment when the article was published. The evidence does not explain why the settings differed, whether the $400 setting affected charges, or how many other sellers had the same problem. The sale-based option appeared for certain listings where the seller could ship the item. A complete list of eligible sellers and countries was not established. This should not be presented as a new worldwide launch or proof that Facebook charges every seller incorrectly.
Why it matters: A seller can work out whether a $10 advertising fee leaves enough money from a $50 sale. An unexplained $400 daily budget makes that decision much harder. For anyone buying ads, the lesson is practical: check what you agreed to pay, what the ad settings say, and what Facebook actually billed you. Those are three separate things. In this test, the first two did not agree, and the final bill remained unknown.
Images: 1 MarketMaze screenshot · Cover AI-generated
