Conversion rate (CR) is the percentage of clicks or visitors that complete a defined action, such as a purchase, a lead form, a registration or a first deposit. In affiliate marketing it is usually measured from tracked click to tracked conversion, and together with the payout per conversion it determines an offer's EPC.
Formula
Conversion rate = conversions / clicks × 100
Define both sides before comparing numbers. "Clicks" can mean raw or unique clicks, and "conversions" can mean every tracked event or only approved ones. A program reporting CR on unique clicks and approved conversions will show a different figure from one using raw totals.
Example
Example: a fintech offer receives 4,000 unique clicks from one affiliate and records 120 approved account openings.
CR = 120 / 4,000 × 100 = 3%
If the offer pays $25 per approved account, EPC is 3% × $25 = $0.75.
What moves conversion rate
- Traffic intent and geo. A visitor from a branded comparison search converts very differently from a push-notification click.
- Funnel length. Every extra step (email confirmation, KYC, deposit) loses users. For multi-step events like an FTD, measure CR at each step.
- Tracking loss. Blocked cookies, broken redirects or missing postbacks look like low CR even when users convert. Check tracking before blaming the traffic.
- Fraud. Bot clicks inflate the denominator and drag CR down, while an unusually high CR on a small source can point to self-referral or incentivized sign-ups.
Why it matters
Brands use CR by affiliate and sub-ID to spot weak or suspicious traffic and to set realistic CPA bids. Affiliates use it to tell a traffic problem from an offer problem: compare your CR across several offers on the same source before deciding which one to drop.
Related: EPC, FTD, click fraud, postback URL.