First post here, but I had to jump in.
If you're buying Danactive because it's "better" or "healthier" for your kids, then you're getting seriously ripped off.
If you look at the ingredients in Danactive, it's (in order): milk, water, SUGAR, whey protein, and then a bunch of preservatives. The active cultures in it are l.bulgaricus, s.thermophilus, and l.casei Immunitas® (a branded name for lactobactillius casei).
If you look at a plain Greek yogurt brand like Fage, the ingredients are: Grade A Pasteurized Skimmed Milk, Live Active Yogurt Cultures . The active cultures are: L. Bulgaricus, S. Thermophilus, L. Acidophilus, Bifidus, L. Casei.
Note: EXACT same cultures in Fage as in Danactive (actually more in Fage, but inclusive of the ones in the Dannon product). No sugar, no whey protein, no preservatives, no fake flavor or color.
I've compared the Fage product to the Kirkland (Costco brand) Greek yogurt and it has the exact same ingredients and active cultures. It's a little less tart and a little more runny than the Fage brand, and I like the Fage better, so that's what I buy. At Costco the Fage 32oz containers are pretty inexpensive. I mix in honey or sometimes a spoonful of preserves or jam, depending on my mood.
I'm sure there are other plain yogurts out there (both Greek and non-Greek style) that are just milk and with the same active cultures.
Honestly there is NOTHING in the Danactive that is special or better for your kid. It's all marketing hype.