Abstract: A method, device and system for the determination of the attention level of an user of a communication device. The proposed invention detects situations when users are more likely to pay attention to content presented to it (e.g. when they combat boredom) or in other words, situations when users are more receptive to content, without requiring the user to perform certain specific activities or requiring any interventions or specific sensors. In order to do so, user data such as demographics, user context, and usage patterns of the user's communication device (e.g. a mobile phone) is collected.