Most importantly it only holds two months worth of revenue data
It makes sense that a free program might have limited storage space - so I expect that there will be a cutoff at some point in the past beyond which Practice Mate will delete the data. But I have seen nothing in print that states what this cutoff date might be. Anyone who intends to use Practice Mate as their primary billing program for a while would be wise to export financial data to Excel on some regular schedule.
From personal experience, I can say that many doctors don't care about what reports the practice management software can generate. A number of my clients pay no attention to the reports that I give them. They know how much money they are putting in the bank (they do their own deposits, not us), they know how many patients they want to see in a week, and so they just put down their heads and work.