What was the best selling album of 2015?

The best-selling album of 2015 was Adele's "25" for several reasons. Firstly, Adele had built up a massive following after the success of her previous album "21," which gave her a significant advantage in terms of fan base and anticipation. Secondly, Adele's powerful and emotive voice resonated with a wide range of listeners, making her music accessible and relatable to a diverse audience. Additionally, the album featured hit singles like "Hello," which received extensive radio play and generated further interest in the album. Adele's ability to connect with listeners on an emotional level, combined with her strong fan base and catchy singles, contributed to the immense commercial success of "25" and secured its position as the best-selling album of 2015.