Do a quick search for China on the page, and you'll see. They are indeed made in China, and there have been numerous reports of quality issues (especially transparency of the figures) with differing degrees of severity. Personally, I love the minifigures enough that I don't notice too
much of a difference, and I would not skip out on buying them. That being said, I haven't gotten any of the ones that are practically translucent if held up to light, so I don't have much of a personal point of comparison.
Some other distinctions are that the necks of the torsos don't have the black marks typically associated with "normal" mifigures, and that their arms have the indentation in them associated with the magnets.