structural:summarization
Legacy

In the 1980s, U2 "dominated the alternative rock scene", according to cultural critic Kevin J. H. Dettmar. Similarly, in the next decade, they were one of the most famous alternative rock bands worldwide and among the highest-selling rock bands. In the 35-year history of Billboard ' s Alternative Airplay chart, U2 holds records for most songs charted (42), most number ones in the 1980s (2, tied), and most number ones in the 1990s (6). Record sales declined in the 2000s and the music industry entered an age of often illegal digital downloading, but according to author Mat Snow, U2 prospered more than younger acts because of a loyal following that held an attachment to the album format. Snow said, "Children of the album era as they were, U2 would never stop regarding the album as the core statement of their creativity", despite progressively decreasing sales, while he noted that live shows consequently became the group's greatest source of revenue.