The FTC Guidelines involving the Use of Endorsements and Testimonials in Advertising has recently been updated after almost 30 years. In short, any "material connections" between advertiser and endorser must be disclosed. This includes any paid advertisers on blogs, websites, online directories, facebook, and all other areas of social media.

Furthermore, any discussion of the product experience must now actually describe what the average customer should expect from using the product. The new regulations take effect December 1st. All violations will be reviewed on a case by case basis, and may be subject to fines. For more info, visit the FTC's press release: http://www.ftc.gov/opa/2009/10/endortest.shtm