Doing business in San Francisco

You might want to also note that San Francisco's business culture is quite casual.

It is not just that the people running technology start-ups will routinely dress in blue denim and a sport shirt (no tie, of course), and call everybody by first name. The same will be true even in long established companies, especially below the very top executive level. The man in jeans that you see being greeted by "Hey, Chuck, how's it going" as he walks thru the office might be just one more low level staff member . . . or he might be the CEO of a multi-million (or billion) dollar corporation.

This is not intended as a sign of lack of seriousness or lack of respect for visitors. Rather it is an indication that what is important is what they are doing, rather than how they are presenting themselves. Someone might be dressed in a suit, but probably only when they are meeting with investors from out of town. Or, occasionally, if they chance to be aware that a visitor is from a culture where such things are considered very important.