Suggestions for technical approaches to Licensing a CRM4 (ISV) add-on

Question

Hi all,

The team I'm working with have created a CRM4 add-on which encapsulates 'standard' CRM customisations (such as modifying existing entities, adding our own custom entities), reports, plug-ins, and our own web pages (in IFrames) and web services. All pretty typical stuff.

I'm writing all the requisite installation code to simplify / automate the install process so that our ISV add-on can downloaded and trialled by anyone, but have been asked to think of appropriate way restrict functionality - to encourage people to purchase a license.

I'm not that familiar with the concepts/best practices/pitfalls when it comes to the 'licensing' of .net apps (especially CRM4 add-ons) so am asking you if you have any suggestions. We're looking for something fairly simple, and should be reasonably 'crackable', since we believe that having to enter a license code is generally a PITA.

• Does the CRM API have anything to offer the ISV developer? (I see that one is able to nterrogate the License entity, but I'm assuming that this is for the CRM license itself)
• Are there any existing code samples / projects / frameworks that are appropriate to use or implement?
• I'm tempted to create a Registry Key upon installation of the add-on which, if after a month the correct license key has not been entered, will restrict functionality. Is this the best way to do this? Have you seen any other add-ons do it differently / better?
• In terms of restricting functionality, I'm thinking of throwing InvalidPluginExecutionExceptions. Surely there must be a more 'graceful' way to do this?

All thoughts and suggestions appreciated.

Regards, Peter.

Answer 1

My thoughts:

• Yes, you can query the License entity to get the number of licensed users, which is a common license type from what I've seen. Lots of 3rd party vendors charge by the number of licensed users, regardless of how many of those users actually use the customization. I try to stay away from these because the license costs are often prohibitive for enterprise deployments.
• Not that I know of.
• I like this option, and have seen at least one 3rd party tool use this method. They allow you to declare the license key in your .config file, and if their runtime doesn't find it there it checks a known registry key. The tool comes with an app that registers the license key in the registry for you. I'd be careful to test and make sure your custom code can read the registry in a least-privilege environment.
• Definitely not graceful to throw exceptions, but it does prove your point. :) Other than that, just outright skipping your code is another possibility, although that could have data implications. If you must throw exceptions, I would suggest trying to run some javascript on form load of your entities that warns the user that their license is expired and a save will result in an error. Some more nefarious schemes could include Thread.Sleep, kinda like the old shareware nagscreens. :)

Another idea - can you set up an Enterprise IFD deployment so you can give customers remote access to your demo, including their own demo organization? This depends on your audience, but your customers may not have the luxury (time, dev environment) of downloading and installing your trial. They may just want to see it in action - once you qualify the sale maybe you offer free remote installation and not spend so much time on a flawless setup package? Again, depends on your audience and the volume of licenses you expect to sell. Technically, you could dynamically provision organizations using the SDK and make the online trial process completely automatic. Of course this is a big investment, but allows you to maintain absolute control over your demo/IP.

Hope that helps!