Good knowledge of the aha moment will give you direction for developing your product. Instead of creating features that no one needs, you will create elements that are essential. Discovering the aha moment is essential to having a good understanding of what people need to engage with your product.
Every great online service has this aha moment. For example, for Yelp the biggest discovery was that users want to write reviews of places, not just read reviews.
Find out what the aha moment is for your product by analyzing data, doing experiments, and talking to your users.