PayPal, the online payment juggernaut, has been the single greatest growth driver for E-commerce giant eBay (EBAY 1.01%) for the last several years.

In the last five years alone, revenue from eBay's PayPal has compounded at an average rate of 18% annually. PayPal's overriding success in the booming industry for online payments has clearly been a major contributor to eBay's outstanding performance. Looking at the last 5 years, eBay's shares have surged 260%, handily trouncing the Nasdaq's 164% gain during the same time frame.

EBAY Chart

EBAY data by YCharts

The best is yet to come
Although this run has been impressive for both companies in question here, there's plenty left in the tank at PayPal to help fuel eBay's returns for years to come.

One particularly interesting area of opportunity for PayPal and eBay is mobile. In just the latest example to date, over the Thanksgiving holiday, PayPal noted an impressive 114% spike in mobile payments compared to the year prior.

As you can imagine, PayPal, and eBay by extension, are laser focused on this booming market, as tech and telecom analyst Andrew Tonner examines in the video below.