Through smartphones and mobile internet connections, collecting data from a large number of users and sensors has become ordinary. Users share information not only through private messages, but also over public available services or in particular applications contributing to data collection projects. On one hand, sensors in modern smartphones enable us to collect a large amount of information without the need to directly interact with the user. On the other hand, users actively share all kinds of information in social networks. However, it is still challenging to motivate a large number of people to participate in collecting data when active contribution is needed. This is particularly critical, when the needed information is of personal nature. In this work, we discuss four approaches to actively encourage users to provide information. Furthermore, we present first results of an online survey evaluating which of the approaches would be appreciated by users to contribute to a health data collection.