1. A method for generating a personalized reaction, the method comprising: collecting, using one or more computing devices, interaction items associated with a first user and accessible to the first user from one or more data sources, the one or more data sources including a social network, the interaction items including an online user post and a user reaction; processing, using one or more computing devices, the collected interaction items to produce one or more labels for the collected interaction items; ranking, using one or more computing devices, each collected interaction item based on the labels and based on the first user's prior reactions to other interaction items and the respective labels of the first user's prior reactions; determining that the online user post satisfies a threshold likelihood of being important or interesting to the first user; and automatically generating, using one or more computing devices, a suggested personalized reaction to the online user post on behalf of the first user, the suggested personalized reaction based on one or more labels associated with the online user post.