If you love yogurt it's worth it to make your own. Then you can control what goes into it and enjoy a cost savings as well.
I found this recipe tucked inside one of my Grandmother's old recipe books.
1) Preheat oven to 275 degrees
2) Measure 4 cups of non-fat dry milk into a large glass bowl.
3) Add 6 cups of cool tap water and stir to mix.
4) Add 3 Tbsp of plain store bought yogurt. (I buy generic, just make sure it has live active cultures)
5) Place loosely covered in oven and TURN OFF OVEN.
6) Leave overnight - from 8 to 12 hours
7) Store tightly covered in refridgerator - it will keep for several weeks.
8) Add desired fruit, honey or sugar but remember to keep some of your plain yogurt aside to start your next batch.
If yogurt seems soupy after 12 hours you can preheat oven back to 275 and repeat process for a few more hours. I've found just having my oven light on keeps the temperature perfect.
When you scoop out some of the yogurt, whey will seep into the indentation. Drain off the whey and the yogurt will thicken.
Remember that too high heat (more than 130, I think) will kill your yogurt.