 This question of defining digital platforms is not simply important for market definitions in antitrust analysis. It also relates to what constitutes appropriate standards of conduct and consumer protection. Traditionally, we could neatly divide activities into lines of business and determine what sort of behaviors harmed consumers. For example, warnings and disclaimers considered adequate for a line of business where risk is obvious, such as skydiving, might be considered inadequate in other circumstances where the risk is less obvious but just as significant. While many businesses operate multiple vertical or non-related operations, digital platforms are unique in the way that they potentially perform multiple diverse functions in diverse markets simultaneously. Comcast owns both Universal Studios, the content company, and the theme park, but consumers have no trouble distinguishing whether they are renting movies from Comcast video on demand as opposed to riding a roller coaster. By contrast, a middle school student might simultaneously use a combination of Google Docs, YouTube, and Google Search to research a homework assignment that traditionally would have been done with a laptop for word processing, books for research, and a librarian to help find relevant material. To learn more, visit digitalplatformact.com to download the free book.