Earlier quoted context omitted.
On a related note, Google penalises websites with longer load times. http://googlewebmastercentral.blogspot.nl/2010/04/using-site...
I understand the reasoning but I don't agree with their implementation, because it essentially favours large sites run by those who can afford the faster infrastructure, while penalising the small ones that may actually have more relevant and detailed content but not very fast servers. Sites which load much faster get a ranking advantage even if they offer only superficial lower-quality content. Maybe if they didn't…
I'd hedge that 95-99% of alexa top 1000 sites could be delivered under 30kb -- just content+ css. (assuming ajax/video/fonts are asyncronous in google's algo and not counted towards load time).
In which case it's easy even for the cheapest AWS server to host and server instantaneously. I think the bigger sites have a distinct disadvantage -- they have so many tracking and ad resources, that it kills their load time.