You could do this with that they are gonna reply to you with their acc/pw ect.
Or use a phishing site.. Well you make it say www.wow-europe.com/blabla/afggjg or something (you hide your domain with something like that)..
Then they enter the pass and so on on your phishing site..
Visited WoW-Europe.com today, and saw they had a event where you can win spectral tigers. So why not use that to a scam, everyone wants to get one of those.. Right..? <.>
Anyway, so the email could include..
Hi this is blizzard blaggawogjkb....
Congratulations you have won a spectral tiger from the random lottery! weee yahhoooo
Well you get the point.. I hope :P
Bye