For many decades, computer software was mostly purchased on a one-time basis for varying lengths of use, usually over a 12-month period. However, this method of purchase is being challenged by software developers who want to increase revenues from this activity for the next eighteen months.

Called "Software Monetization Models and Strategies 2021", the survey conducted by Revenera with 374 people would have questioned the profitability of the sector. More than half of IT and software companies plan to move to subscription models in the next year or so. The main reason why these publishers prefer subscription (monthly) or license (yearly) to one-time purchase is that it will allow them to get better revenues in the long run.

In order to make their offers attractive, most publishers offer special deals that allow users to test the software for a short period of time. During this time, they can either confirm their purchase by subscribing permanently or cancel the offer if they are not convinced by the service provided.

So far, "the monetization models that dominate the industry are subscription and perpetual license. Subscription means that users, instead of buying software, pay a specific monthly amount to keep their software account running, while perpetual license means that users will get a software license for a few months or for a specific period of time, after which they will have to buy it back. 

Source : Developpez.com