A lot of the licensing systems I've encountered cause problems if you're selling to big corporations because they don't work well in locked down environments. Whatever you use needs to have an alternative way.

The other question is the ease of integration and the cost of the software - if you spend weeks integrating and troubleshooting it, I'd be tempted to forego it for anything but a high-value product.

Keep in mind that troubleshooting it will be an ongoing process when some paranoid BOFH has locked down the user's machine to the extent that they can't do anything, including their job.