I do not think it that they do not care, more that they have no mechinism or resources to so the proper management and notification. A simple web tracking application of current users in a SQL database (or access) should be created, and the email sent when the fix is posted. Use something like the Persist ASPEmail application and queuing feature and you can post several thousand messages in a matter of a few seconds with minimal over head (the queued email connects to the SMTP as needed thru a control panel service and does not cause a delay). You can even track bounced back emails. If the system is SQL driven, the unique keys or licenses could be generated for each individual client and attached to the email as a memory attachement. If anyone at CuteSoft is interested, I already have a standard ASP application and SQL database that is very similar to this and could be easily modified to your match your needs.
RC
p.s. the Persist Tech support is worse