Cost Per Lead (CPL)

CPL makes channels comparable: if Google Ads delivers leads at $80 and a directory delivers them at $45, the directory looks better, until you check quality. The metric that actually matters is cost per qualified lead, or further downstream, cost per closed customer.

A cheap lead that never answers the phone is more expensive than a costly one that closes. Always pair CPL with close rate before reallocating budget.

CPL also varies predictably with intent: bottom-funnel search leads cost more per lead but convert at multiples of top-funnel social leads. Judging both on the same CPL target quietly kills your best channel.