It's much cheaper to work and live in Daly City than in San Francisco. It's probably a lot easier to expand there as well. If you buy office space in San Francisco, you either buy just enough for your current team with some wiggle room, or you buy as much as you think you need for the entire time you plan to remain there, which may be 2 or 3x the size of your current needs. It costs a lot of money to own property you're not fully utilizing, but companies do it, many sub-lease the space to offset the cost, but for smaller companies, this means they move offices pretty frequently. My company is in their third office in just the past year :P
Actually, there are regulations in SF about leasing space you don't actually need. I don't know all the details, but my employer just moved to a new Soma office and we were prohibited from having a huge meeting space, and instead had to partition it and use some as workspace.
Ah OK, I guess my direct experience with larger spaces comes from the south bay, but all the same, this explains why my current office keeps moving! So this still highlights what is probably a benefit of places outside of the city :)
I'd bet Yishan lives in the peninsula or south bay and didn't like his hour-plus commute into sf. Public records say Palo Alto, so yes -- he wanted a much better commute.
They'd lose a ton of sf employees though; it's a shit commute for them.
