An internet surfer clicks his mouse in London, and an electrical impulse shoots down his phone line. The signal then flits along a copper wire to his telephone exchange, before being fired at near light-speed via a fibre-optic line to a cable buried under a beach in Cornwall.
After a 4,700-mile transatlantic journey that takes just 72 millionths of a second, it ends up on a server farm in the American Midwest. There, powerful computers will begin churning through hundreds of thousands of pieces of data to create a profile of the Londoner.
Less than 200 millionths of a second later, the computer will have fought a welter of other machines in an online advertising auction. Read entire article here>