Most major cities seem to offer tours in large often open topped double decker buses, in London you can even go on amphibion ducktours which can go in the river as well as on the road.
But Gocars SF have taken a different approach and offer funky 3 wheel moped cars with an automated GPS, complete with a voice tour. They have expanded to San Diego and also Miami . .and you can buy your own franchise for around USD 50K-100K.
Perspective: This is “Frontiering” use of technology to promise a new and different way to see a city, and because the experience is so different, consumers are in a sense advertising the service as they use it! In addition, it’s one experience that would be hard not to talk about, so Gocars SF will benefit from “Word of Mouth Marketing”.