Ran a two day conference with a packed schedule and people kept telling us after previous events that they'd meant to catch a specific session but just lost track of time and missed it entirely. This time attendees could bookmark sessions they cared about right in the mobile app, and it pushed a reminder a few minutes before each one started. Noticed way fewer people wandering in five minutes late asking what they missed compared to past events, the reminder actually did its job. Review collected by and hosted on G2.com.
Push notifications depend on people actually having the app installed and notifications turned on, and a decent chunk of attendees just used the browser version without ever downloading anything, so those people got zero benefit from this at all. Review collected by and hosted on G2.com.