Originally Posted by quantum-x

Campaigns are useful for tracking certain.. campaigns, but do not replace the need for individual site linking.

For example, I have the following campaigns:

Default:
Streaming Video:
Search Engine:

If I could only link by campaigns, I would have no way of telling which site got what traffic, and from where.

If you dont use campaigns etc, then they may seem redundant. From my experience, they're a good system.