Are businesses measuring the wrong lead metric?

Most teams still celebrate “number of leads generated.”

But in my experience, lead volume is often a vanity metric.

A campaign that generates 500 low-quality leads can be worse than a campaign that generates 30 serious buyers.

Curious how others think about this:

What metric do you trust more?

1. Cost per lead
2. Cost per qualified lead
3. Cost per meeting
4. Cost per opportunity
5. Revenue by source

For founders, marketers, and sales teams — what do you actually track?