That stat comes from the fact that the (emdebian-grip) rootfs for the product I am currently working on is about 60Mb unpacked, and after you do your first apt-get update at which point it is about 100Mb. Those numbers are from memory, but the point is that on a small system the overhead is significant. Debian's package list alone is 25Mb, and the package cache is another 13Mb on this box I have to hand. This desktop box has 60Mb of apt cache and package lists. Clearly 60Mb on a 4Gb system is not a big deal at all, and even on a 60Mb system we still find it useful enough that we choose to use it. We used to use ipkg which is enormously slimmer, and necessary if you don't have the storage to support apt/dpkg, but apt/dpkg do work a lot better when things get a little complex.