PayPal said it will pay up to $100 million in promotional incentives to customers who use the service on up to 100,000 merchant sites in North America.

In a statement, the unit of online marketplace eBay Inc. said millions of PayPal customers will be eligible to receive cash rebate offers up to $20 when paying with PayPal from November 23 through May 15, 2007. Qualifying merchants include the sites of Barnes & Noble Inc. , Dell Inc. , Petsmart Inc. , Starbucks Corp. , Art.com and a portion of the Hewlett-Packard Co. site, PayPal's site said.

A free shipping promotion also begins on November 23. Shares of eBay were up 59 cents, or 1.8 percent, to $32.98 in early trading on Nasdaq on Monday.