HN user
Pros
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0) It's validation.
1) Execution will be different, they might bork it or serve different customer segments.
Cons
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0) Find/create durable competitive advantage/s
1) Win-Lose/Lose-Lose competition sucks because it's often dumb (see also: Peter Thiel)
I would like to see that bookstore toured on Periscope.
"Idea guys" are mostly useless: the people that want credit for "thinking of something" and kick back while everyone else works. More often than not, they're deluded and "in love" with "their" "great" ideas that deny reality in high-def cognitive dissonance. (They're usually wantrepreneurs or enterprise busywork titles.)
What set SJ apart was positive value (being right more often than not, building people up to produce better work products than they thought the could, a determined direction, actual vision) on balance outweighing negative traits (histrionic tantrums, treating employees like shit, generally acting like an asshole).
A cautionary note: If someone is going to play the eccentric jerk role, they'd better be actually right nearly always and bring metric fucktons of net positive value by the containership-full to the business, staff, customers, partners and other stakeholders.