What is ROI (Return on Investment)?

ROI (Return on Investment) is profit relative to campaign cost. It is the primary success metric in arbitrage: whether the buyer earns on the gap between ad spend and offer revenue (including rebills).

Formulas

• ROI = ((Revenue − Cost) ÷ Cost) × 100%.
• ROI = (Profit ÷ Cost) × 100%, where Profit = Revenue − Cost.
• Sometimes ROI 100% means doubling money (profit = cost).

Example: revenue $1,500, ad spend $1,000 → profit $500 → ROI = 50%.

What counts as cost

Ad spend, network fees, proxies, creatives, domains, tracker, holds/chargebacks. Clean ROI imports cost into the tracker and compares to approved revenue from postbacks.

ROI vs ROAS

ROAS = Revenue ÷ Ad spend (spend not subtracted). ROAS 1.5 = $1.50 revenue per $1 spent; ROI 50% on the same numbers. E-commerce often uses ROAS; CPA arbitrage uses ROI or absolute profit.

Practice

Daily routine: reconcile cost and conversions → ROI per campaign/sub_id → pause below break-even ROI, scale winners. Rebills and LTV raise long-term ROI above the daily snapshot.

See also: ROAS, CPA, EPC, tracker.