Google spam expert Matt Cutts took to YouTube this week to warn brand marketers who don't fully disclose advertorials or native advertising as ads. In a video he talks about guidelines, links and disclosures to search engine and readers. He points to several sites in the United Kingdom believed to take "money and writing articles for pay, including keyword-rich anchor text in the articles that float PageRank and not tell anyone." Cutts explains some of the issues surrounding advertorials and native advertising.