the daylight bulbs aren't the same - they're designed to give off a more natural light balance for people doing sewing/painting/crafty stuff. The proper SAD lights give off a broader spectrum of light, similar to natural daylight, which is why it works. I found a SAD light for about £90 in Boots a couple of years ago. It's strange - it can give you a bit of a sickly headache at first, a bit like motion sickness, but this wears off over time. You do have to persevere with them though.