I was looking at getting one of those. I think you still have to buy store yogurt for a starter. I read that book French Women Don't Get Fat and apparently the author swears by her yogurt maker. I recently tried a Greek yogurt called Fage that is really really good. It's very thick and creamy and they have a full fat version, 2% version, and fat free version. I've tried the full fat and 2% and they both rock. The fat free is always out of stock when I go to buy it so it must be pretty good. It's pricey but good. If you add a bit of honey to it it's like a softer cheesecake. YUM.
Not only is the yogurt less expensive when made at home, but it tastes better too. I save--on average--$4.75 per pint of organic yogurt when I make it at home. If you consistently make yogurt, you don't have to worry about buying more starter because you always have some available with all the good live lacto-bacteria like L. Acidopholus and L. Thermophilus.
The yogurt maker was one of our best kitchen purchases, and it's super easy to use: heat the milk to almost boiling, cool it in the fridge for about twenty minutes, mix in your starter, set it on the counter overnight and in the morning you have yogurt. The yogurt I make tends to be smoother, creamier and sweeter than the store-bought plain yogurt. I don't need to sweeten it at all.
Once you get the hang of it, you can start making stuff like labneh (yogurt cheese) which is a really tasty substitute for cream cheese.
Yes ... I love that yogurt maker. SO worth the money.
Fresh Yogurt Maker? (good for hormone free?) 
