I was a little skeptical about these when I heard about them, but I tried them. I live alone so there arent a lot of lights ever on, but I would estimate these things save me about $20-25 a month. The bulbs themselves are a little more expensive than a regular bulb, but each bulb is supposed to last 5 years. The bulbs I bought draw 26w but are as bright as 100w bulbs, or the equivalent of ~4 times more efficient.
Seems like a good investment- Walmart seems to have the best deals on these (not so much Home Depot, Sam’s or Lowes).
Has anyone else tried them?