Cause that seems a bit...Well bad to say the least. What's stopping me from doing this with your link:
httptrans.html?uname=fahadsadah&pass=yourpasswordw hichigotfromoneofyourlinks&creds=481&transto=Livew ire
Seriously; thats probably why it's not there already - your password CANNOT be exposed in an HTTP GET or anyone who wants it just has to cut and paste. Especially with the transfer script.
And I know what you're thinking - you could easily track me down for using that link and get your credits back.
But what if I'm not the one who clicked it? What if I make that same link but substitute GamingX for Livewire? Any tracking information available for who clicked the link, even if it's by IP, won't stand up well - I could just go to any public place so the IP'd come back to anyone else in the same building (head to the college and it'd show up under one of any of their four ip's - tracking that down to a single user would be difficult at best - tracking ME down would be impossible since you'd have an ip not tied to a username).
It's a good idea and all, but theres also a reason it's not there yet - you can't expose personal information via HTTP GET cause it's a highlight+copy away from being stolen.
Edit: Sorry for putting the name GamingX in there too; was the first name I could think of besides Corey >_<