"_RankPay uses proven SEO practices to achieve rankings and abides by industry standards, including: credible link building, relevant blog postings, trusted social bookmarking, and select directory submissions in order to build a consistent, customized SEO program for each and every customer. _
Our SEO Team has partnerships with hundreds of publishers, blogs, and directory sites. Nearly all RankPay SEO activities result in permanent exposure, even if the program is no longer in Active status. We work with our partners to identify relevant context for opportunities to further strengthen our customer's SEO programs."
So basically they use white hat, and on page to rank for terms they know they can rank for, they most probably do not take on all clients, only small to medium businesses that can see easy results in an easy market, by white hat.
The issue I see in this, is there is no longterm business growth strategy, only the putting of all eggs in the Google Keyword basket, in the hopes that these terms will make money.
I am with Matt, cannot give a opinion on whether to use it or not, but it really depends on is all you are trying to do is get keywords? Then it might work for you.....