Amazon is the biggest web-based retail platform. Amazon operates through its websites in the US, the UK, Ireland, Canada, Germany, China and a few more countries. Apart from selling a large amount of goods, divided into various categories, Amazon offers a wide range of products and purchasing subscriptions. Amazon also manufactures and sells electronics such as Amazon Kindle e-book, Fire TV and Fire tablet computers. Another Amazon service, the Kindle Direct Publishing, provides the possibility for independent authors to publish their content and gain exposure for their books. Amazon shares are traded on the NASDAQ stock exchange. The company is a member of the NASDAQ-100 index, the S&P 500 index and the S&P 100 index.