Free programs intrigue me.  I used to have a difficult time understanding how they made money if the product was free.  Infrastructure and staff cost money, right?  One day Joel came in and told me, “If it’s free then you are the product”.  It took me a minute to understand what that meant.  You being the product means that anything you use the product for is no longer privately yours.  Free email uses all the email contents for advertising and marketing purposes (which is where they get their money).  Large file transfer programs that are free do the same thing.