EPC (Earnings Per Click)
EPC, or earnings per click, is revenue divided by the number of clicks. It is the single most useful comparison metric in affiliate marketing because it normalizes sources of wildly different volume onto one number.
EPC stands for earnings per click. It answers a deceptively simple question: for every click a source sends, how much money comes back? Because it collapses volume, quality, and payout into one figure, EPC lets you compare a boutique affiliate sending 100 clicks against a super-affiliate sending 100,000 clicks on equal footing.
The formula
EPC is just money divided by clicks:
EPC = revenue ÷ clicks
Which "money" you divide by depends on who is asking. As the program owner you usually care about revenue EPC (received ÷ clicks) to judge whether a source pays for itself, and profit EPC (profit ÷ clicks) to judge whether it pays you. An affiliate looking at their own portal sees payout EPC (payout ÷ clicks) — their earnings per click, not yours.
A worked example
An affiliate sends 4,000 clicks this month and drives 80 conversions worth $2,400 in revenue, on which you owe $1,600 in payout.
- Revenue EPC = 2,400 ÷ 4,000 = $0.60
- Payout EPC (the affiliate's view) = 1,600 ÷ 4,000 = $0.40
- Profit EPC = (2,400 − 1,600) ÷ 4,000 = $0.20
Now a second affiliate sends only 500 clicks but drives 20 conversions worth $900 revenue. Their raw conversion count is a quarter of the first affiliate's — but their revenue EPC is $1.80, three times higher. EPC is what surfaces that: the smaller source is far more valuable per click and probably deserves more volume, a better payout, or an exclusive offer.
Why EPC beats raw totals
Total conversions reward whoever has the most traffic, not whoever has the best traffic. Conversion rate tells you how often clicks convert but ignores order size. EPC folds both in — a source can win on EPC through a high conversion rate, a high average sale, or both — which is why it is the number experienced buyers optimize toward.
How this works in LimeliJourney
Every summary in LimeliJourney's reporting carries an EPC column computed from the exact clicks and revenue in that view, so you never reconcile it by hand. Bot and duplicate clicks are excluded from the denominator by default, so EPC reflects real visits rather than inflated traffic. Affiliates see their own payout EPC in their portal; you see revenue and profit EPC in yours. Because payouts are frozen at click time, an EPC you read today for last month never silently shifts when you edit a contract. You can also ask LimeliChat "which affiliates have the highest EPC this quarter?" and it pulls the same figures and flags the outliers.