Improper Format Scammer, impersonator: Pixel_pro, cl0k..

Victim:
|steamID: WhiteDynamite
|steamID32: STEAM_0:0:29776237
|steamID64: http://steamcommunity.com/profiles/76561198019818202
|customURL: http://steamcommunity.com/id/WhiteDynamite
|steamrepURL: http://steamrep.com/profiles/76561198019818202

Scammer:

|steamID: Pixel_Pro
|steamID32: STEAM_0:1:21732403
|steamID64: http://steamcommunity.com/profiles/76561198003730535
|customURL:
|steamrepURL: http://steamrep.com/profiles/76561198003730535

So first of all he claimed to be this guy: http://steamcommunity.com/profiles/76561198031549787
http://imageshack.us/photo/my-images/18/scammerzw.png/
after I sent him a key, he didn't reply and changed his name:
http://imageshack.us/photo/my-images/43/scammer2p.png/
then I checked that guy thread again and clicked on his name and realized that this guy that i gave a key is a scammer..and that's all he didn't reply nor deleted me from his friendlist.

Its not a big loss, but still i rather give it to a friend then a scammer.

Why is it improper?