When we started looking around for a new LMS to replace Angel (our old LMS) one of our online faculty started a full campaign for Canvas. None of us had even heard of Canvas (this was in 2011), but this faculty member had a Free for Teachers (FFT) account and raved about how amazing it was. The members of the LMS Committee got Free for Teachers accounts and started playing around with Canvas (important course content over and building from scratch) and trying it out with their students.
We checked out other LMS's, but kept coming back to how easy it was to use Canvas and how much students seemed to really like Canvas. The Committee ended up unanimously voting for Canvas and the rest is history! Yet, we continued to rely on FFT accounts when faculty were interested in checking out Canvas (prior to the implementation) and I know some of our adjuncts still use it for classes not taught at our Institution!
Free for Teachers for the win!