When people think about marketing costs they might think about advertising costs, social media costs, man hours etc.
Smart companies will consider some other marketing costs/opportunities. Sometimes it’s worth selling a product or service at cost (or even below cost) in order to establish relationships. If you can create a business relationship that can be turned profitable later (assuming you can afford to do this) you can generate sales that don’t positively impact profitability but can be considered part of marketing costs.
The challenge is to make sure you can differentiate between marketing costs vs a bad business plan. If you are selling at cost, or lower, with a plan to build the business going forward, this could be considered a good marketing cost.
Have a great day!