Yes. Here are some history and stories about eBay and Paypal.
In October 2002, PayPal was acquired by eBay for $1.5 billion. PayPal had previously been the payment method of choice by more than fifty percent of eBay users, and the service competed with eBay's subsidiary Billpoint, Citibank's c2it, whose service was closed in late 2003, and Yahoo!'s PayDirect, whose service was closed in late 2004. Western Union announced the December 2005 shut down of their BidPay service but subsequently sold it in 2006 to CyberSource Corporation. BidPay subsequently ceased operations on 31 December 2007. Some competitors which offer some of PayPal's services, such as Wirecard, Moneybookers, 2Checkout, CCNow and Kagi, remain in business, despite the fact that eBay now requires everyone on its Australian and United Kingdom sites to offer PayPal. Eventually eBay moderated its position, and mandated that sellers on eBay Australia offer PayPal as one of the (but not necessarily the only) payment methods. These accepted payment methods include bank deposit, cheques and money orders, escrow, and credit cards (processed by other than PayPal).
In January 2008, PayPal agreed to acquire Fraud Sciences, a privately-held Israeli start-up company with expertise in online risk tools, for $169 million, in order to enhance eBay and PayPal's proprietary fraud management systems and accelerate the development of improved fraud detection tools.  | 
