The question -- what are the business motivations for buying on Alibaba.com -- is a little vague. What follows assumes the questioner's intent is to inquire regarding Alibaba's role in the wholesale, rather than retail, sector.
Wholesale is that part of the commercial sector that sells to retailers. In other words, a wholesale manufacturer or distributor's customer is the store visited by the individual consumer. The wholesaler sells items in bulk to a department store chain or other type of retail business, which, in turn, sells those items to families and individual consumers, with the price increasing each step of the way. In addition to its entry into the retail online shopping industry, Alibaba also markets itself as a wholesaler, providing bulk sales to retail outlets. Below is a link to an online wholesale distributor of automotive parts, Motovicity.com. This company specializes in selling auto parts in bulk to auto parts stores, which sell to individual consumers looking to repair their cars. The business motivations for buying on Alibaba.com, therefore, are the same as in the retail sector. Are Alibaba.com's prices competitive? Is it a reliable distributor (i.e., are the items that were ordered by the retailer shipped on-schedule and do they arrive in good condition)? An additional consideration, however, that is unique to China involves regulatory considerations. Does the Chinese government impose an undue regulatory burden on foreign customers that make it bureaucratically cumbersome? The same can be asked of the U.S. government, especially where exports of certain types of goods are concerned, but the United States government and regulatory structure -- despite their flaws -- are far more transparent than those of China. Finally, China's judicial system, which may need to be approached in the event of a serious disagreement with a China-based supplier, is far from impartial and highly susceptible to corruption, placing American and European customers at a distinct disadvantage.