It's always good to give a little back, be it by helping someone cross the street, helping a friend rearrange their house, or in this case, help others download files on the internet. You may not know this, but times when you have to download large files they can get corrupted or stop downloading before they should, leaving you with wasted time and the prospect of having to download them all over again; then there's the occasional hassle of downloading files from far away so they run very slowly.