PayPal, the online payment service owned by marketplace eBay, plans to launch up to $100 million in promotional incentive programs during the holiday shopping season.

The company said Monday the incentives will include cash rebate offers up to $20 when shoppers use its service on eBay.com and other qualifying merchant Web sites in North America. Free shipping will be offered for some of the Web's most popular brand names.

Dana Stalder, senior VP of marketing and business operations for PayPal, said in a statement that the incentive program is meant to attract buyers and drive more sales to merchants. The rebate program will be available from Nov. 23 through May 15, 2007. Free shipping promotions also begin Nov. 23, with no stop date set.

To qualify for the promotions, online merchants must offer PayPal Express Checkout.

Online retailers are gearing up for what's predicted to be a strong holiday shopping season. Sales are expected to increase 18% this year over last year, to $32 billion, according to JupiterResearch. A record 114 million people are expected to shop by mouse to avoid the long lines and crowds at shopping malls.

PayPal claims to have nearly 123 million user accounts worldwide.