Reed Diffusers

I love to find different ways to pleasantly scent the house. I love the idea of reed diffusers: small sticks that suck up essential oil and scent the room. I just got the latest catalog of Yankee Candle and found the neatest Halloween Reed Diffuser Scene. It's a purple bottle with black sticks in a graveyard with scented stones and such. The problem is that reed diffusers don't work. I've received a few as gifts and they just don't scent the room. Have you had any luck with reed diffusers? What do you think about them?