Why does the type of user information posted on user's profiles at Wikipedia differ from the profiles posted on Facebook and LinkedIn? Our research examines the differences in the types of information users share on their profile pages in online volunteer communities like Wikipedia. We analyze the structure of user pages as well as the types of information which users share. We summarize our findings into a theoretical framework to better understand user motivations and the relationships between the type of information on user's profiles and their involvement in Wikipedia. In place of an actual name, connection to a network, pictures and friend lists on social networking sites, Wikipedia editors provide different information such as education, age and field of study on their user pages. Through a qualitative analysis of more than 100 active user profiles, we found patterns which help us develop a theoretical framework of the types of information that Wikipedia editors share on their profiles and how and why it differs from user profiles in online social networks. We also hope to explore the use of user profile information to gauge user motivation.