E-commerce data
COGS (cost of goods sold)
What it cost to acquire or make the products you sold. Without COGS, profit cannot be calculated and assistants can only talk about revenue.
COGS is what it cost you to acquire or make the products you sold in a period. It is the first number needed for any profit calculation: gross profit is revenue minus COGS, and POAS and contribution margin build on that. Without it, an assistant can only talk about revenue, however many systems it is connected to.
In practice COGS lives at the product or variant level. Shopify stores it in the cost per item field, other platforms in similar fields or in metafields, and some businesses keep it in a spreadsheet or an inventory tool. Coverage is the usual problem: if half the catalogue has no cost recorded, every profit figure that depends on it is wrong in a way that is hard to see.
A useful first task for an assistant with store access is a coverage check: which products are missing a cost, which have costs that look stale, and how much recent revenue those products represent. Fixing that data improves every profit question asked afterwards, including the signals sent to ad platforms for profit-based bidding.