Copyfitting

http://www.tpub.com/content/draftsman/14066/css/14066_44.htm
This is a website I found on the internet about copyfitting. Copyfitting is a process that allows you determine how much space is needed for the copy within a layout. The copy itself can also be adjusted by font size, letter spacing, word spacing and/or line spacing to make to make the copy fit the designated amount of space. This is the only website I have found so far that explains how to copyfit text by hand. It gives two methods: the character count method and the line measurement method. This website gives step-by-step instructions on how to do these two processes - but I'm not so sure I understand!

http://www.designingwithtype.com/5/copyfitting.php?type=intro#
This is another website I found about copyfitting that just shows a simple diagram of a block of copy that is sectioned off into 5 columns. This was done in order to calculate the character count. Number of lines X characters per line + extra characters = character count. Spaces and punctuation are included as characters.
But what do you do with this information once you calculate it???