Well my house gets damp pretty easily so hanging too much stuff up on radiators etc is not really great... Especially in winter. Hanging on a washing line takes too long... we have a tumble drier and to dry 6kg of clothes (which is a lot), it costs under 30p... That's the equivalent of 3 minutes minimum wage... 3 MINUTES!!!!! Why waste time, make the house damp and have clothes absorbing the radiator heat? (It takes heat to evaporate the water which you will only get back if the water causes damp)... Plus the tumble drier heats the house as efficiently as an electric heater, and provides distilled water for ironing