Amazon, Apple.com and Walmart together make about 100 billion dollars of e-commerce turnover (2017 figures), which however covers less than 10% of the market share, showing that the market is still quite fragmented (a share that increases if we take into consideration the GMV). In detail we see the gross merchandise volume (GMV) of the top e-tailers then and we get a fairly realistic view of those who are the top players, based on the latest sales data available (source: Activate).

Market share (2017) of top global e-tailers, based on the gross merchandise volume (GMV)

We all know Amazon, but it is useful to know that in 2017 it grew by 15.9% in terms of net sales with the USA, Germany, France, UK, Italy, among the major markets. Regarding the other e-tailer mentioned, maybe a further info is needed:
TMall.com is one of the platforms of the Alibaba group, active in China, and also has a version (Tmall.hk) that handles cross-border e-commerce transactions. A special trade regime for those who adopt a business model that does not provide direct legal entity of the company in China and that allows you to sell your products to the final consumer as if he went to our shop during a trip outside of China. Obviously there are spending limits (for order and total annual spend), but it is a regulation born in 2016 in China that the government aims to expand with a view to further facilitating the flourishing Chinese e-commerce market. The investments are not even remotely comparable to some western marketplaces (logistics costs aside, important investments are needed in marketing and promotion of visibility, engagement of a third Chinese party agency that manages the store, and several other relevant costs).

One of the TMall mega-events in China (for 11/11). The stage recalls the kitten of the logo, of course

JD.com is the marketplace of the Tencent group (a major rival of the Alibaba Group among the Chinese tech giant) with almost $ 55.5 billion in turnover and over 300 million active users. Since February 2018 it has been investing heavily for a more deep-rooted presence in Europe, and in the meantime has announced two important operations: the first is the partnership with Metcash for online sales in the grocery sector (everyday shopping), certainly strategic in a country in which from HeMa (Alibaba group supermarket) you can have a truly cutting-edge offline-online shopping experience, paying from smartphones, having quick delivery at home even of the cool, and numerous other features that envy the West (app that exploits the gamification of the hippo-symbol and many other innovative features …). The second is the sale of one’s financial arm.

Taobao is always part of the Alibaba group and has over six hundred million active users, mainly aimed at C2C: transactions between users for the sale and purchase of e-commerce, as could be eBay in the West about ten years ago. Among the innovations that develop the group there are adaptive technologies on research that also adopt semantic approaches, and especially the possibility of profiling the huge user base through the big data that they generate, crossed with other platforms that include social media, entertainment channels, consumer finance tools and much more.

Rakuten, on the other hand, is the leading platform in Japan, which in 2017 reached over 7.3 billion euros in turnover and manages over a third of e-commerce transactions. In the middle of this year it seemed to want to launch its own crypto-currency similar to Bitcoin after the acquisition of a California startup, but after the last events of the speculative bubble on the crypto-currencies, there are doubts on the actual implementation. Although, IMHO, could bring added value on micropayments related to content making, but I see little affinity with the mainstream marketplace approach of the group.

Pinduoduo

Among the remaining ones I would like to highlight only an emerging small player (if we can define it considering the absolute value of the GMV share): Pinduoduo that scored an IPO in the United States, collecting over a billion and a half dollars. In fact it is an e-commerce platform that offers a very wide catalog of products from the categories related to everyday shopping (grocery) up to appliances, but implements in the purchase process a native social component that the company defines team purchase. In practice I can share product and information in my circle of contacts and followers on social media, such as WeChat, and get a low price linked to my suggestion. A process that invites interaction, sharing and makes the shopping experience even more dynamic and interactive, thanks to the possibility to check out better prices playing in team with friends, contacts, followers. We should all keep this one on the radar