Every founder I talk to has the same GA4 dashboard open: pageviews up, conversion rate flat (or dropping), and zero idea why.

Here's the thing GA4 fundamentally can't do — it aggregates. It'll tell you 1,200 people hit your checkout page and 340 converted. It will never show you the 860 who didn't, or what they were actually doing in the seconds before they left.

That's the gap session replay + heatmaps fill:

• Rage clicks & dead clicks — if 40% of mobile visitors are furiously tapping a button that isn't registering, no funnel report will surface that. A 30-second replay will.

• Form abandonment, field by field — heatmaps show you exactly which input field visitors stall on (usually phone number or a confusing address field) before they bail.

• The "it worked on my machine" problem — a broken CSS state on Safari/iOS that tanks your checkout completion rate won't show up in aggregate analytics at all. It just looks like "conversion rate dipped 6% last week, unclear why."

The pattern I'd push back on: teams add more analytics dashboards when what they actually need is observability into individual sessions. Funnels tell you where people drop. Replays tell you why they dropped there.

If you're running paid traffic and your checkout/signup conversion rate has been flat despite "optimizing," the fastest diagnostic isn't another A/B test — it's watching 20 replays of sessions that dropped at your worst funnel step. You'll usually find the leak in under an hour.

That's the whole idea behind what we're building at LeadFnF — happy to answer questions on setup or privacy-safe replay (no cookies, no consent banners, sensitive fields masked client-side) if anyone's curious.