> We like domain expertise, but empirically it's not critical.
That's quite a statement. Companies like AirBnB are exceptions, not rules. If you look at most of the top tech IPOs in 2013, which is as legitimate a way as any of identifying companies that have actually delivered liquidity to employees, there's domain expertise everywhere. Examples:
Veeva - founder was previously at salesforce.com, PeopleSoft, IBM
Marketo - founders hailed from Epiphany
FireEye - founded by a former Sun Microsystems engineer
Zulily - founded by Blue Nile execs
Tableau Software - founded by university researchers who specialized in data visualization
Rocket Fuel - founders all worked in ads at Yahoo
RingCentral - founder previously sold a software
communications company to Motorola
Pretending that you can spot the next Mark Zuckerberg or Brian Chesky is a fool's errand if you're a prospective startup employee. Domain expertise doesn't guarantee success, but it is more likely to minimize certain risks, particularly those around market fit and sales.
> It's rare for a startup to succeed without making money for the employees though.
A founder who owns 4% of a $1 billion company gets a $40 million pay day when his company goes public. And chances are he's going to be receiving more equity if he's still a member of the management team. An employee who owns .01% of a $1 billion company gets a $100,000 bonus when his company goes public. Even if you own .1%, you won't net $1 million after taxes. This is not the type of "making money" many early startup employees are after.
Simply put, the idea that owning a smaller piece of a bigger pie is better than owning a bigger piece of a smaller pie doesn't stand up to scrutiny in Silicon Valley because most startups don't go public at billion-dollar valuations and the vast majority of M&A deals are under $50 million. The odds that you are going to work at Facebook in 2006 or AirBnB in 2009 are not very high.
Heck, the odds are that you won't even get an exit, so why not work for (or with) somebody who isn't figuring things out for the first time?