According to iChinaStock.com, one of China’s top consumer shopping websites, 360buy (aka – Jingdong Mall), has blocked eTao, a leading e-commerce search engine, from crawling its pages. The decision is another indication that the e-commerce sector is getting more competitive and each of the leading companies is looking for ways to be uncooperative with perceived competitors.

In this case the perceived competitor is Alibaba Group which owns eTao along with its own portfolio of e-commerce platforms: b2c shopping website, Taobao Mall (aka – Tmall), c2c shopping website, Taobao Marketplace, and b2b shopping website, Alibaba.com Limited(01688.HK).

According to research firm Analysys International, Alibaba’s Tmall accounted for 32.8% share of China’s B2C e-commerce market in Q2, followed by 360buy (12.4%), Amazon.cn (2.3%), Suning (2.2%) and Dangdang (1.4%).

So while there is no question that Taobao Mall is a direct competitor to 360buy, it isn’t clear how blocking eTao’s access to its pages impacts anyone but 36obuy. Users of eTao will no longer be able to find 360buy product information and user comments.

Apparently this uncooperative behavior is common among the top e-commerce companies in China. eTao’s owner Alibaba blocks Baidu, Inc. ((ADR) NASDAQ: BIDU), the leading Chinese search engine, from indexing  Taobao Marketplace and Taobao Mall.

The real question is why Alibaba and 360buy believe that limiting their visibility on any search engine — even ones operated by e-commerce competitors — will benefit them. Even if they felt that these search engines were providing more favorable natural search rankings to their related shopping websites, withdrawing completely does nothing to challenge those results.