Create an application that will expire after a trial period
C# 2008 SP1
I am writing an application that I want to give to a select number of customers.
What is the best solution to use so that after the trail period (1 month) the application will no longer work.
I was thinking that if they are interested in purchasing the software I will give them a license key or something, to unlock the application.
I am have a very limited budget as I am working on my own. So is there any free 3rd party products that does this?
Answer
If you go with a date-based approached, it can be circumvented by a user's setting their date back (although I doubt people do this very often). An alternative is to allow the application to be started a certain number of times before expiring; this approach obviously ignores any date changes.
My preferred method is to disable parts of the application that are critical to normal use of the program but aren't critical to its evaluation (like the ability to save your work, for example). I do this with my own software, and then send them an unlocking code unique to their computer when they purchase the full program. One primary advantage of this approach is that the installed demo functions as a potential sales tool forever. I'd rather have my program always working to some extent; I don't think a "Sorry, this program has expired" message generates many sales.