I bought this because I'm affected by changes in weather, and even a couple of days of cloud and darkness can leave me in a pretty deep funk if I'm not careful to do something to alleviate it, like vigorous exercise. I had been thinking about purchasing a lamp for SAD for years but whenever I checked out prices they seemed to be incredibly expensive, and until I found this one (they were £35, now £49 for some reason) I had resigned myself to the fact that I couldn't afford one.
Firstly I ought to say that this is really effective at what it does. It's very, very bright. An hour sitting right in front of it in the morning after I wake up makes a very big difference to my day if the weather is bad, so I'm very pleased with my purchase.
However, I've realised that the reason it is so much cheaper than other SAD lights is that it doesn't resynthesize the mains frequency to alleviate flicker, so while the lamps that cost 3 or 4 times as much as this put out about the same amount of light they don't noticeably flicker because they contain electronics that shift the flicker outside of our range of perception. Sitting a foot away from this you can REALLY see it flickering, which is a bit straining on the eyes. Still, if you can't afford a more expensive lamp then this is a very good compromise, and even with the flicker it's better than not having it.