Final answer:
The fourth category of social media typically refers to social news sites, such as Reddit and Digg, where users can influence the visibility of submitted content through voting, driving public discourse and sociological implications.
Step-by-step explanation:
The fourth category of social media mentioned by Dollarhide and Drury includes several types, but one prominent category is social news. These are platforms where users can submit news articles or content and vote on them, influencing their visibility and prominence within the community. Examples of social news sites include Reddit and Digg. Such platforms facilitate topic-based and controversial discussions, which can significantly impact public opinion and decision-making processes.
Additionally, these platforms illustrate how digital media shape our social interactions and alter traditional forms of sociality. They enable quick dissemination and debate over current events and social issues, thereby influencing collective attitudes and behaviors. As our engagement with digital media evolves, so too does our understanding of sociological concepts and their application in the modern world.