The ease of use, ability to get updates or new features when they become available with no additional fees! It's free up until you receive an invoice from them that is $50/month after which it becomes very expensive (though I understand why). They are constantly improving this software as well; however, some things still seem "unfinished" but don't let those disappointments discourage you! We have been using FMC since about 2013, though we were not 100% satisfied at first because there was soโฆ