I think it is up to the posters. Just happens to be that everyone chooses to have it off.

Makes more sense logistically - it's more convenient to have all questions/mails about the job coming in to an email address.

But why not parallelize repeated questions? Clearly those interested wouldn't just comment "I'm in". They would email.

Probably because repeated questions isn't a problem yet.

Heh, I was just wondering the same thing.

What do they mean by London/SF? Which is it? Would I have to move to London?

The plan is to be in San Francisco, but we need someone who is flexible and willing to be in London if necessary for the good of the company. (e.g. our UK founders get delayed with visas, etc.) Its much more productive to be working in the same location.

Is it easy for someone from the USA to get a work visa to work in London?

Easier than the other way around, put it that way. We're building an international team with a global mindset, so that flexibility is essential.