Shares in eBay have jumped almost 8% after the online auction site's Paypal unit said its revenues would double by 2013 to between $6bn (£3.7bn) and $7bn.
Payments service Paypal could be eBay's largest business within five years, chief executive John Donahoe said.
"We are driving the next generation of e-commerce," he added.
Last month, eBay reported profits of $559m for the final three months of last year, in part thanks to a big jump in revenue at Paypal.
"We're at an inflection point where tech-driven innovation is broadly shaping e-commerce and shifting consumer behaviour," Mr Donahoe said.
"This shift is creating new global opportunities for our company."
The company has implemented a number of changes as part of three-year turnaround plan, including a revamped website and search engine, lower upfront fees, and the launch of mobile applications.