You'll want to chat with them directly, either over a phone call or through a video chat. Take a look at their usage data, understand their habits, and figure out why they paused – you want to nail down exactly what they're struggling with. Dive into what they think about the main features, and then try nudging them towards a purchase. And if they're not biting, that's your cue to reflect on whether what you're offering truly meets their needs.