[jrs235]

Prior to monthly or annual subscriptions, business software was purchased for a larger lump sum up front and perpetually owned. If you wanted to get updates and support you often paid a yearly maintenance fee ranging from 10% to 30% of the initial license/software cost. Saas, Software as a service was originally paying a monthly or annual fee for the software maker to also pay and run the servers. Now it seems Saas stands for software as a subscription where that still applies but everyone expects continuous never ending features to be added.

[valuearb]

For corporate software maintenance as mandatory, making it little different from subscriptions.