Cheap leads feel like progress until the sales team stops calling them back. A better way to judge a campaign.
The comfortable number
Cost per lead is the easiest number in the account to move and the least connected to revenue. Loosen the targeting, soften the offer, drop the qualifying question, and the number falls. Nothing about the business improved; the reporting simply got more flattering.
What to measure instead
Pick the first action that a salesperson would describe as real: a booked meeting, a site visit, a trial with activation. Feed that event back to the ad platform as the conversion. Optimisation follows whatever you tell it to chase, so the definition of success has to sit downstream of the form.
The trade you are making
Expect lead counts to fall and cost per lead to rise the week you make this change. That is the point. The number that should fall is cost per closed deal, and that takes a sales cycle to show up. Tell your stakeholders before you change it, not after.