In-content ads work similar to in-image ads: We semantically analyze the text, section by section, and match it to our advertising categories. Ideally, we are animating the text sections and are displaying the ads in between the relevant sections. There is a delay corresponding to the reading time up to the text section. This increases the viewability and ultimately the CPMs.
On mobile devices, we can easily follow the users attention by his scrolling behavior and display the contextual relevant ad just at the right point of time. The user is not interrupted in his navigation and can continue reading.