Originally Posted by Jdoughs

Just to elaborate.

- if you buy links based on pr you don't know what you're doing
- if you buy links based on alexa you don't know what you're doing
- if you buy links based on traffic you don't know what you're doing
- if you buy links based on backlinks you don't know what you're doing
- if you buy links based on domain age you don't know what you're doing
- if you buy links based on archive history you don't know what you're doing

But if you have a clue, you use a combination of such things to deduce what is a quality link and what is valuable as an asset for an inbound link.