I've always been a fan of street vendor hot dogs, specifically boiled Sabrett's dogs (or hot sausages) on a steamed bun with spicy mustard, ketchup, and sauerkraut. But I've noticed over the years that despite specifically seeking out the vendors with Sabrett's signage, I often get dogs that I'm fairly certain are not Sabrett's. These impostor dogs are not nearly as salty as real Sabrett's (the impostor hot sausages are missing the "hot"), and lack the distinctive "snap" or a Sabrett.
I've found these dogs most often in kind of touristy neighborhoods, such as Times Square (where the dogs are absurdly expensive), outside the Natural History and Metropolitan Museums, and occasionally in some of the city-run green and white carts in Central Park (which, admittedly, do not advertise their dogs as Sabrett's).
What gives? Has anyone else had this experience? Are they allowed to use the umbrella but not sell the dogs? It's annoying enough that I have restricted myself to buying them from locations that I know are on the level.