1. That’s how we sometimes introduce first-timers (usually kids) to the idea of riding, it’s easier to balance especially in the taffic jams and isn’t as dangerous for first-timers;
2. The space between and over two back wheels may be used for a motor, a battery and a place to put your luggage on.
3. They have a good marketable slogan already in the name, as they are Try-cycles.

You just need to design it to cool and\or professional so the rider won’t be afraid of looking like a kid or a clown.

Pro and con: it’s width is way more than that of a bycicle, but at the same time it gives a bit of wiggle space for your feet.