I don't know if this is what your average buyer is thinking, but the big plus for any time-traveling character (DC or Marvel), is that, even with a successful cinematic universe, you're eventually going to want to do a reset so you can re-cast some of the bigger roles that actors have fulfilled their contracts on, but that you still want in movies. A good way of doing that is with a timeline reset through some sort of time travel story. I suspect that the MCU's Kang storyline is going to culminate with some of the major characters from Phase 1 being recast and brought back as alternate versions.
Also, Doctor Who has become more popular than I ever thought it would when I was a geeky kid in the '80s and none of my schoolmates had ever heard of it; I wouldn't be surprised if people just like Booster just because of the time travel element.