ROI (Return on Investment)

ROI is (net profit ÷ investment) × 100 — the general-purpose profitability ratio applied to any spend, not just advertising. This is an economics metric, which means it is only useful next to the other numbers in its chain. On its own it can be gamed: a great number on a tiny denominator tells you nothing, and a poor number can be the correct trade for volume. Read it alongside spend, order volume, contribution margin and the time window the platform used to attribute the result. Read it next to ROAS (Return on Ad Spend), POAS (Profit on Ad Spend), MER (Marketing Efficiency Ratio).

The calculation itself is simple — ROI = (Net Profit ÷ Investment) × 100 — and the judgement is entirely in the inputs and the window you choose. Treat the metric as a decision rule, not a scoreboard. Write down the threshold at which you would scale, hold, or cut before you look at the report — then let the number answer that question. Segment by campaign objective, audience temperature and creative concept, because a blended figure hides the two or three line items actually moving it. Worked through: $40k profit on $200k marketing investment → ROI = 20%.

Pull the number from one source of truth and keep the window fixed. Platform reporting, your analytics suite and your order system will disagree, usually because of attribution windows and refunds. Pick the system your P&L trusts, note the window, and compare like-for-like week over week rather than chasing daily noise. Why this matters commercially: Where ROAS is a media metric, ROI is a business metric. It's how finance evaluates whether a campaign or channel earned its keep.

Xeli reads this metric back to the creative and the SKU that produced it, so the next production run is weighted toward what actually paid. Instead of a spreadsheet reconciling creative names to results, each rendered asset carries its concept, offer, ratio and product ID — which turns the metric into a brief for the next batch. In the context of metrics & economics, that means the concept stops being something a person re-applies by hand every campaign and becomes a rule the system enforces on every asset it produces.

The recurring problems are predictable: confusing roi with roas (roas is a multiple, roi is a %); only counting media spend as investment. Each of these is a process gap rather than a knowledge gap — which is why the fix is usually a checklist, a template or an automated rule instead of more training.