Using the 2017 Taiwan Communication Survey data, this study integrates the perspectives of "motivational news use" and "incidental exposure to politics" to explore the types of news and political information use on social media and the predictors and consequences of different uses. We identify four types of users. Nearly half of users who frequently express themselves are more likely to incidentally encounter political information on social media. Furthermore, the results indicate that incidental exposure to politics facilitates political talk but has limited effects on exposure to the number of online news outlets. The other half of the users are classified into three other types. They differ on personal background, exposure to online news outlets, and political talk.