A method for detecting if an online review written by a user on a website of a telecommunications network is a spam, using at least one previously-labeled review, a review dataset comprising at least one review to be analyzed, and a spam feature list listing different features of spam reviews, method wherein: a) a weight is computed for each spam feature of the spam feature list, corresponding to the importance of the spam feature in the detection of spam reviews, and based at least on the features of said at least one previously-labeled review, and b) a probability of being a spam for a review under analysis in the review dataset is computed by using at least the weights of the spam features computed at step a) and a comparison between the features of said review under analysis and the ones of at least one review previously-labeled as spam.