Avantages
The name is the main reason someone works for this company. There is no eBay/PayPal discount or any shared benefits of their many other companies' services. They have a small gym in San Jose at both PayPal and eBay locations you can use. No free lunch. The cafe is OK, but about the same cost as others in the area. The location is unique, not near many other start ups. PayPal is at least close to mass transit.
Inconvénients
The company has weak incentive plans and stock, so these shouldn't be considered in salary negotiation. Ebay has been working to try and catch up and lose the auction stigma for years, but is still fighting for turnaround. There is considerable red tape and they talk about things being done on 2 year roadmaps instead of the more common Bay Area '2-6 week' cycles.