| I do some of this on a limited basis.
I base my price solely on traffic - I don't beat my chest about PR nor would I sell a link based on PR. But, if you can prove hundreds of thousands of visitors a month to a site and offer to link to a genre related, relevant site, it's going to catch a serious webmaster's attention.
That's not to say that a high PR site wouldn't get attention and sales, I merely sell based on my traffic and hence the ability to potentially send another site some of that. |