http://h10010.www1.hp.com/wwpc/uk/en/sm/WF06b/3709945-3709945-4202225-3722810-3722810-3794423-3794432.html

I don't make things up :) And we always put 2 in for redundancy!

Here's some CoLo prices, too:

http://www.redstation.com/colocation.html

So, figure at least £1400pcm for a single rack in a single data centre. There's probably loads of extras you'll need too.

But whatever, Pete - we clearly disagree on a number of things such as "industry standard" and "world class".

Well, firstly, I don't believe you can run something that big on rented hardware. Facebook has over 800 million users.

Let's say you store just 500 kilobytes of data per user. That's

800,000,000 * 500 = 400,000,000,000 kilobytes.

400,000,000,000 kb = ~372 Terabytes of storage alone.

Secondly, even if it as all rented and managed by someone else - you're still going to pay for it!

I just think Pete's got his head in the clouds on this one.

I have a feeling it's going to involve some kind of peer - peer stuff where bits of data are stored on peoples machines or some such. Even ignoring the security issues there, I still think it would be horrendously unreliable and I don't know what happens with mobile stuff.

I just Pete has massively underestimated what it genuinely costs to run something on the scale of Facebook. I don't doubt one could write a better platform and so on, but I think they'll all get cold sharp shocks when they try and scale it into the millions of users.