In the context of cold-start items the popularity bias is important because it might happen that many items, even if they have been in the catalogue for months, received only a few interactions. This creates a negative loop in which unpopular items will be poorly recommended, therefore will receive much less visibility than popular ones, and will struggle to receive interactions. While it is expected that some items will be less popular than others, this issue specifically refers to the fact that the recommender has not enough collaborative information to recommend them in a meaningful and reliable way.