How come the blizzard downloader is so slow?

ok the new patch 4.0 is available for download and i can't play wow without downloading it. the blizzard downloader is extremely slow and the average time for it to complete it says is around 10 to 15 hours. thats a bunch of bullshit in my opinion. nothing else is running on my system. i dont see why its so god damn slow. anyone know why? blizz pisses me off with this ****.|||Modify your downloader settings so it wont throttle background or something like that when you modify it its gonna give you some sort of warning saying it will slow you down hit yes and enable peer to peer sharing if all goes to waste then try this portforwarding site it has alll the Guides find your router and follow the steps