Natalia noticed two bottles of sunscreen side by side at CVS. Initially, it appeared that one was a great deal because it offered 33% more volume at the same price: sort of a reverse Grocery Shrink Ray. Turning the bottle over, though, she read that the bottle had a little less of each of the effective ingredients: about 10% less by volume than the smaller bottle. Doesn’t that mean you have to use more sunblock to get the same effect? [More]