The early grunge movement revolved around Seattle's independent record label Sub Pop and the region's underground music scene. The owners of Sub Pop marketed the style shrewdly, encouraging the media to describe it as "grunge"; the style became known as a hybrid of punk and metal. By the early 1990s, its popularity had spread, with grunge bands appearing in California, then emerging in other parts of the United States and in Australia, building strong followings and signing major record deals. Grunge was commercially successful in the early-to-mid-1990s due to releases such as Nirvana's "Nevermind", Pearl Jam's "Ten", Soundgarden's "Badmotorfinger", Alice in Chains' "Dirt", and Stone Temple Pilots' "Core". The success of these bands boosted the popularity of alternative rock and made grunge the most popular form of rock music at the time.