Is the UK the only country that does it that way? I wonder why it never caught on (or if it did, why it was eventually replaced) in Canada and Australia, for instance. It definitely makes for great viewing seeing all the candidates stand together, but it can also make watching the results kind of anti-climactic.
Interesting question. I don't know the answer to this, but presumably it dates to when the secret ballot was introduced in the late 19th century (with public balloting of course you can't wait to announce until they're all counted). My guess would be that it has to do with travel times. The thing about the UK is that the ballot boxes are physically transported to a central location before counting - but this would be logistically kind of nuts in 1870's Canada or Australia.
The trouble with the British method is that it sadly means we get no data below constitiency, which is very sad for map-lovers.
