On one of the websites I'm working on the Site Analytics are broken - a MongoDB database is successfully created by Sitecore to store Analytics data and I can see the Analytics interface in Content Editor, but no visit data is actually recorded in MongoDB. I've found a short guideline from Sitecore itself, but it wasn't particularly useful. I couldn't identify any particular errors from the logs, so I'm a bit clueless as to how to proceed.
What are the steps I could take to debug my Analytics Data issue? I know this is a bit too broad, but I presume there aren't too many fail points.