When I joined my 1st startup (10 years ago next month – yikes!), we were in the business of selling software licenses. Companies placed orders, we shipped them, invoiced them and moved on. We didn’t really know if the company was having success with our software. Sure, we asked. But, we could not know for sure whether they were using our stuff.
In this era of hosted web services we can and should measure everything we can. We no longer have to rely on a customer or user telling us if they use our stuff. We know it because we can track detailed info about who the user is, how she uses the service, how you acquired that user, etc, etc.
Starting with stats