Amazon starts charm offensive as merchants defect to Wal-Mart

Amazon can ill afford to alienate the more than 2 million merchants hawking goods on its site.

For years, Amazon.com Inc was the go-to place for online merchants. 

Increasingly, however, the e-commerce behemoth has competition for the hearts and minds of millions of mom and pops. Wal-Mart Stores Inc is successfully courting many of the same merchants. Alibaba Group Holding Ltd's Jack Ma was in Detroit last week dangling millions of Chinese web shoppers before US businesses. In July, eBay Inc will host its annual seller celebration in Las Vegas.