YouTube, the world's most popular video-sharing site, will start to sell music and video games and experiment with new advertising formats to grow revenue, executives said on Tuesday. The Google-owned business is taking the first steps toward building an e-commerce service through which it will sell music, films, TV shows, video games, books, concert tickets and other media-related products featured on the millions of videos on YouTube. Visitors to YouTube.com can buy songs from music videos they watch on the site by clicking on buttons that take them either to Amazon.com Inc's MP3 store or Apple Inc's iTunes store. YouTube users will also be able to buy video games, such as Electronic Arts Inc's sci-fi game "Spore" through the Amazon link. Amazon and iTunes will share revenue with YouTube when users buy content through the partnership.