Once a shop generates revenue, it can begin to measure success by looking at its bottom-line profit number. This is the money that's left in your bank account after you've paid for your apparel item, the transfer/ink/consumables, the labor to apply decoration, and any other expense associated with the decorating of a product. When you first start heat printing, this bottom-line profit number can get eaten up quickly.
We have to consider turnaround times and how much it costs us to ship our items from suppliers. Any hiccup in our production or pricing models could mean reordering shirts or rush shipping transfers. The list of mistakes that we make when learning how to price and produce high-quality products goes on. And each error can drastically reduce the bottom-line profit number.
Sources: Josh and Zach Ellsworth, Stahls'