This study aims to investigate the cultural heritage as a strengthening factor in the social media engagement. The research is based on a content analysis conducted on 3200 posts published on Facebook by a sample of 64 medium-size and large companies registered in the “Register of Long-lived Firms” of Italian Chamber of Commerce. The Register involves firms with uninterrupted activity in the same business industry for at least 100 years. The calculation of the indices of likeability and shareability and a multiple regression model has made it possible to measure the effectiveness of posts in increasing social media engagement and verifying which dimensions are most used by the sample companies