Alibaba beats estimates as e-commerce powers ahead

It's the world's biggest online shopping event.

China's annual Single's Day looms again later this month.

It will probably mean another bonanza for e-commerce giant Alibaba.

Second-quarter revenue at the firm rose a forecast-beating 40 percent.

The gains were driven by strong online sales, and by its cloud computing business.

Alibaba earns most of its money from selling ads and promotional services to merchants on Tmall and Taobao -- two of its e-commerce sites.

Total revenues for the period rose to nearly 17 billion dollars.

Challenges lie ahead though.

Sales growth has been slowing in China's big cities, forcing Alibaba to double down on reaching shoppers in provincial towns.

Meanwhile, upstart rival Pinduoduo has won customers with its social, group-buying app.

A share sale might be part of the answer.

Reuters sources say Alibaba could conduct an IPO in Hong Kong as early as this month.

It's estimated that could raise as much as 15 billion dollars.