True, but I've found that it rarely gets done right, and this does nothing to prevent convection. You're right when you say the cost is lower though. Sure, as with many other products, it can fail if it's not installed properly. I disagree. Turning the house in to a beer cooler is another way of saying that you're doing a perfect job of preventing unwanted air leakage, especially in to the attic. Air exchanges should be provided by mechanical equipment, not holes between the living space and the attic. It definitely depends on your climate, but here in Minnesota, tiny air leaks in to the attic can equate to huge moisture problems with the attic.