Well gitftp is a neat little tool that allows you to push your unstaged changes directly to your FTP.
While this is entirely true, some of us are still stuck in FTP hell. And besides, if you have an SFTP access, wouldn't you be better off doing pulls directly from your server ?
Because that's a great way to force you to have the same code locally and on your server. Also, that's how my workflow is. So yeah, it's mainly because I like it suits me. ;-)
As simple as a Blink 182 song :
git clone git@github.com:jevin/gitftp.git
cd gitftp
ln -s gitftp /usr/local/bin
Lastly, be aware that all your FTP credentials will be stored in the /projects folder!