I'm also from Utah and have eaten at Waffle Love's trucks and store multiple times. The waffles are amazing - seriously the best I've ever had! And as a side note, the brick and mortar location is pretty tiny (and shared with another local business). Still a storefront though!
Waffle Love has a huge Instagram following (in comparison to the other competitors) and they posted frequently during the race asking people to spread the word to friends in Sedona, etc. I think their use of social media has definitely played a part in how they've been able to do so well.