I have one adult paysite, 5 years, currently page rank of 1, but previously 6. Also have 40 free sites, all with seperate ip's, many with a page rank of 1. I use the free sites for linking to pay site.
My next step is to pay for linking to my free sites to build those page rankings and in so doing increase the rankings of the pay site. But I feel I should get some expert advice first.