Session replay is sold as empathy. Press play, and a stranger’s thumb becomes a story. Beside a mature App Analytics stack it can even be useful: a broken field, a rage tap, a permission dialog that looks innocent in a funnel and cruel in motion. The cost is quieter than the demo.
The first cost is appetite. Once a team can watch, they watch instead of instrumenting. Events stay vague because the video will “explain it.” It will not, not at volume, and not six months later when the clip has expired and the dictionary is still a rumour.
The second cost is legal and social. Masking is incomplete more often than vendors admit in the hallway. A name in a photo, a message in a preview, a workplace in the background. United Kingdom data protection is not a mood; it is a set of duties. If your privacy notice talks about analytics cookies and your engineers are watching full journeys, the documents and the product have drifted.
A narrower watching
If you keep replay, bind it. Sample. Time-box access. Forbid fishing in support’s spare hour. Pair every clip used in a critique with the event that should have made the clip unnecessary. That pairing is the only way I have seen App Analytics and replay live in the same house without the former collapsing.
Api Maphub does not teach a replay vendor. We will, in Funnel Geometry, ask whether a leak is a measurement problem or a filming habit. Often it is both. The cheaper repair is almost always the event contract, not another hour of cinema.