Magazine fallout is a term used to describe the effect of a magazine's circulation decline on its advertising revenue. It is caused by a decrease in readership, which can be due to a variety of factors such as competition from other magazines, changes in consumer preferences, or economic downturns. The crossword solution for the term magazine fallout is 'inserts', which refers to the promotional materials that are inserted into magazines to increase their circulation. Inserts are often used to attract new readers and to encourage existing readers to renew their subscriptions.