According to recent report by Sophos, phishers are persistently targeting PayPal and eBay users. The reason? Ubiquity of the services. eBay is available in 27 countries, and I doubt there are many people who haven’t bought, sold, or at least browsed for goodies.
That’s a big market to go after. Add the fact that there are probably a lot of casual internet users (i.e. not so technologically sophistiicated) on eBay, and you have a big, targeted market for phishers.
I love stating the obvious.