Buy Links to your Web Site
Everybody successful company buys links to its website. Think about it: the entire business model of the largest search engines (Google, Yahoo, MSN) is build on selling links to your website. Of course they prefer to charge you anytime someone clicks on your link versus letting you pay a monthly fee. But if paying an uncertain amount is not for you you should consider buying links to your web sites for a monthly fee.
What the best sites for you is to buy links from depends on the purpose of you buying the link. If your goal is to increase your Google PageRank you should focus on high PageRanks of the sites you ar buying links from. But also make sure they are within your particular 'cluster' a search engine term for industry or genre. If the goal for buying the link is to create more traffic to your site (from that link) focus on the Alexa ranking and cluster of the site you are buying the link from.