pr3-pr5 rated sites. How to make money off them?

Ok...so i have been buying high page ranking sites...with the url's that fit solid into keyword indexing, i have made into amazon referal sites (install the software that grabs items from amazon and posts them to your site when someone is searching, then get commission for the sale). Making between $500-800 a month per site.
I have a number of other high page ranking sites, but their domain names arent key word friendly.
Any thoughts on how to monetize these domains?

Make a small network and use them for backlins to your other sites, current or future. Make sure you use different hosts and etc.. You don't really have to monetize each site, though, you could still do that with, selling links from them to other people

@omaron...ok...i am more of a sales guy...not tech savvy, but like what you are suggesting. So lets say i have 30 of these ranked sites...i set them up as blog sites or some other type of site? once i have this "network" of sites going, then i just bounce the traffic off my already existing sites?
Why is it important to use different hosts?

If you build your sales sites yourself, you are tech savvy enough. There are many posts here about how to build a blog network, just search for it. But basically, you will install some CMS on those domains (wordpress, preferably mixed with something else like Joomla and/or Drupal) then you add some content on those sites and use that content to build back links to your other sites, to boos them in serps. This is not specially to send traffic to your other sites, but link juice to rank them better (which will cause them to also get more traffic).

The point of different hosts is to avoid footprints, send links from different IPs to your other sites. If you will read about blog networks you will find way more details.

Another idea: You can use some of them to sell any links, buf if you are making 500-800$ a month, probably is better to youse the domains to support your blog network because 5 of 10$ will no make difference.