You could talk to your users... (i.e. UX research), observe them using your website or product and ask them non leading probing questions to see what the intent is behind the behaviors affecting your bottom line. Qualitative research methods are a rich source of insight that is typically underinvested and underutilized.

Analytics (quantitative data) can help you find areas of bottlenecks to explore further by doing qualitative user research and getting to the ‘why’ behind the people problems standing in the way of your metrics you are tracking (retention, adoption, etc.). This is called ‘triangulation’ using quant and qual research methods to understand your users more deeply than just looking at data can achieve.

Could be that, it could be design, it could be how something is worded, it could be that what you want the client to see, isn’t being seen. Analytics helps to identify this problem. For instance I noticed recently a huge drop-off in visitors from Ipads, and a redesign apparently made some parts of the site dysfunctional for some ipad users, something we didn’t catch earlier.