There's some matrix-style SEO going on in this post. Not only did Priceconomics.com get great keyword-rich anchor text links from that guest-post article, but

There's some matrix-style SEO going on in this post. Not only did Priceconomics.com get great keyword-rich anchor text links from that guest-post article, but they are also driving links to the article, creating more SEO value for the links that they got. Nice work! Watch and learn people...