Methods, systems, and apparatus, including computer programs encoded on a computer storage medium, for displaying, within a web page, a representation of a content sharing interface, the content sharing interface including a content input area, receiving user input to the content input area, in response to the user input, expanding the content sharing interface to include an expanded content input area and a distribution interface, the expanded content input area displaying a graphical representation of digital content that is to be distributed, receiving user input to the distribution interface, the user input indicating contact(s) to which the digital content is to be distributed, in response to receiving the user input, displaying an icon within the distribution interface, the icon being a graphical representation of the contact(s), and in response to the user input, transmitting a post data set including digital content data and distribution data to a server computing system.