Methods, systems, and apparatus include computer programs encoded on a computer-readable storage medium, including a method for providing content. Publisher input is received regarding acceptable content item types and sizes for inclusion with other content in a publication. Publisher input is received regarding how often content items are to appear in the publication. Identification is received of a user device that will render the publication as an article. The other content is evaluated including formatting the article as a single scrolling page, including defining logical pages with boundaries determined by formatted content blocks and based on display capabilities of the user device. Based on the evaluating, content items are selected for presentation along with the other content when presenting the article on the user device, including dynamically determining a number, types and placement of content items based on the logical pages and properties of the user device.