LinkedIn lead gen forms: optimize for cheap fills or for leads sales accepts?

Say a SaaS company runs LinkedIn lead gen forms at around $40 a lead, and sales says a big share of those leads are students, job hunters, or people who tapped the form by accident. The platform shows a healthy cost per lead, so the easy move is to keep feeding the form and call it a win. I'd push the campaign toward a conversion sales has already accepted, even if cost per lead ends up two or three times higher.

The cheap form is cheap because it attracts the easiest audience, and the algorithm will keep finding more people like that. Volume changes the answer, though. With only a dozen leads a month, you probably don't have enough qualified signal to optimize on, so tightening the form questions is the better first step. Has anyone moved the objective to a CRM-qualified event and seen the numbers hold up?

A rule I'd use: if sales rejects more than a third of leads, stop reading the campaign by cost per lead and use cost per accepted lead instead. Only switch the objective once you have around 15 accepted leads a month, or the optimizer is mostly guessing.