Well it has come to my attention that most people have programs that they claim don't work that they use to swap gamertags with. However I have private programs that do work. I can run up to 8 programs at a time, since I have 4 computers. Two PC's will be on one internet, and the another two will be on another. As far as my speeds go, one connection I have is roughly 50 upload, and 20 download, while my other connection it 300 upload and 150 download. I will be offering this service for free.
Disclaimers:
I am not responsible for any tag that is lost in the process. (Although this will be very rare)
The tag must have been off the market for at least 1 month, patience is key.