Some of the startups in SF are pretty small, just ramping up in terms of head counts and may not have someone in charge to deal with travel logistics (you could be the first remote dev ever).
If you're trying to get a signal regarding whether the company is going to pay you and pay on time, request a tighter payment schedule, e.g. net 10. That reduces the risk a bit on your side (you won't end up working for two months for free) and isn't much different on their end.
If you're trying to get a signal regarding whether the company is going to pay you and pay on time, request a tighter payment schedule, e.g. net 10. That reduces the risk a bit on your side (you won't end up working for two months for free) and isn't much different on their end.