I'm pretty sure that time the Jane Austen Society called for a month of local chapter bingo games made me more sales than being on TechCrunch ten times.
That said, with a view to giving people the best possible advice, I've been told by people who are deeply in the Valley ecosystem that the fact that TC and whatnot are for better or worse the paper(s) of record for the Valley ecosystem means that you probably do want to be in them when you are hiring/seeking funding/etc, both for visibility and for social proof. Be that as it may, there are many, many, many companies which will succeed in selling millions, raising funding, and hiring employees without ever having a single visitor from TC et al darken their doorstep.
That said, with a view to giving people the best possible advice, I've been told by people who are deeply in the Valley ecosystem that the fact that TC and whatnot are for better or worse the paper(s) of record for the Valley ecosystem means that you probably do want to be in them when you are hiring/seeking funding/etc, both for visibility and for social proof. Be that as it may, there are many, many, many companies which will succeed in selling millions, raising funding, and hiring employees without ever having a single visitor from TC et al darken their doorstep.