It's a widespread phenomena.
Usually it's related either to scams, or they try to infect your system with a trojan: in any case they draw your attention in order to persuade you to click on a link. Just to be sure, you can take a look at the real address of the link before clicking.
Anyway, keep in mind that eBay always greets you with your real name plus your username, while the authors of these spam e-mails usually greet you with a "Dear eBay member" since they obviously don't know your personal data and send the same e-mail to thousands of addresses.
Usually it's related either to scams, or they try to infect your system with a trojan: in any case they draw your attention in order to persuade you to click on a link. Just to be sure, you can take a look at the real address of the link before clicking.
Anyway, keep in mind that eBay always greets you with your real name plus your username, while the authors of these spam e-mails usually greet you with a "Dear eBay member" since they obviously don't know your personal data and send the same e-mail to thousands of addresses.