In the online marketplace, consumers can transact business without the constraints of time or distance. One can log on to the Internet day or night and purchase almost anything one desires, and advances in mobile technology allow advertisers to reach consumers nearly anywhere they go. But cyberspace is not without boundaries, and deception is unlawful no matter what the medium. The FTC has enforced and will continue enforcing its consumer protection laws to ensure that products and services are described truthfully online, and that consumers understand what they are paying for. These activities benefit consumers as well as sellers, who expect and deserve the opportunity to compete in a marketplace free of deception and unfair practices. The general principles of advertising law apply online, but new issues arise almost as fast as technology develops - most recently, new issues have arisen concerning spaceconstrained screens and social media platforms. This FTC staff guidance document describes the information businesses should consider as they develop ads for online media to ensure that they comply with the law.