How much money do those Silicon Valley companies burn every month?
Insane amounts, it seems. If Fred Wilson's post is correct (and I see no reason to doubt it), the average pre-revenue seed company is burning as much as $50k a month. Companies trying to accumulate users double that. And companies trying to "build the business" spend as much as $250k every month.
Compare this with London (hardly a cheap city), where most startups that I've dealt with (and whose accounts I've discussed with them) burn anything from £0 to maybe a few thousand pounds a month - at least until they hit revenues - and then try to grow organically.
It's a different world... One wonders why Silicon Valley VCs don't invest more here. If burn rates are an indication, building a business is about 10x cheaper in London than in Silicon Valley.