By the late 2010s, it was estimated that the total audience of esports would grow to 454 million viewers, with revenue increasing to over 1 billion. The increasing availability of online streaming media platforms, particularly YouTube and Twitch, have become central to the growth and promotion of esports competitions. Despite viewership being approximately 85% male and 15% female, with a majority of viewers between the ages of 18 and 34, female gamers have also played professionally. The popularity and recognition of esports first took place in Asia, seeing significant growth in China and South Korea, with the latter having licensed professional players since 2000. Despite its large video game industry, esports in Japan is relatively underdeveloped, with this being largely attributed to its broad anti-gambling laws which prohibit paid professional gaming tournaments. Outside of Asia, esports are also popular in Europe and the Americas, with both regional and international events taking place in those regions.