The article breezes over how they got their foot in the door, but I would imagine it happened gradually (bigger and bigger customers) and then...

"Their big break came when they approached Rotodyne..."

Have to be careful not to compare how they do business now, with how they did business when they were operating from a "garage". I would assume that they (the co-founders) were essentially their own world-class sales team in the beginning and their reputation now replaces that function entirely.