Edited excerpt from What Happens at Y Combinator:
If a company is launched and has users (about a quarter are before they come to YC), then the conversations at office hours tend to be about the various things that happen to actually launched companies. The most common problem is that users don’t like the product enough.
This is normal; it’s to learn where your initial hypothesis is wrong that you launch. Now at least you have some evidence to analyze. So for companies at this stage, the conversations at office hours tend to be about how to figure out from available evidence what users want, how to get more data about what they want, and how to reach more of them.
(1) “Some companies achieve primary product market fit in one big bang. Most don’t, instead getting there through partial fits, a few false alarms, and a big dollop of perseverance.” From Four myths about product-market fit.
(2) As well as analyzing the usage data you have, try also Sean Ellis’ approach in How to identify your product’s “must have” experience.
(3) More from Y Combinator on this topic: Six simple questions to test product-market fit and competitive advantage.