Buying Links - How to evaluate a site?

[Williamsburg]

I've been looking at a number of sites. Most of which are not in the business of selling links; I'm appoarcing them as a 'sponsor'.

How can I evaluate one site vs the next?

- Traffic number (if available)
- Google PR from the toolbar
- linkdomain: function in Yahoo
- Current SE rankings
- Teoma: If it's a resources sites

Also, the question becomes how much is reasonable?

[peewhy]

Put yourself in 'clients' shoes.

Forget PR, if you conduct a search and find them high in the ranks then so do others.

[FourDegreez]

Number of impressions on a given page would also be important. Also, the visitor demographics.

[Williamsburg]

From a 'media buying' perspective the math is easy:

Cost / Expected Clicks = Cost Per Click. Based on historical numbers, I understand what CPC work.

But, purely from a linkpop perspective... Anyone have ideas? What are the keys you look for?