The present invention relates to a method for performing a detection of a topic of a message introduced in a real-time customer service messaging platform. In the method a message comprising at least one word from which the topic is definable is received; a topic from the received message is extracted; it is inquired from a database if the topic is determinable from a number of messages received chronically earlier than the received message; and an indication is generated to an operator of the real-time customer service messaging platform in accordance with a detection result obtained through an inquiry to the database. Some aspects of the present invention relate to a network node, to a computer program product and to a system.