Other networks have scooped up and put out other superhero shows in the last few months, including Marvel's Runaways on Hulu. Not that Netflix should worry about losing its lead, with a second season of the hit series Jessica Jones out next March and a spin-off of Riverdale based on teen witch Sabrina Spellman coming someday. But fleshing out its shared Marvel universe has been a valuable draw for the streaming provider: Only the CW's "Arrowverse" and its crossover events have rivaled Netflix's connected shows.