Why is the BITS service set to manual?

Microsoft's SUS technology uses the BITS service to download updates. Why is this service set to manual? Is it good practice to set it to automatic in case of reboot or whatever? How would it start otherwise? I've noticed it will start itself. If you could clear this up for me, I would really appreciate it. Thanks! The BITS service is started and stopped on its own. It's similar to the Windows Installer technology, in that it only runs when it is needed. For more information on BITS, visit the .
MSDN site