I am going back in time here in the early 1990s
This was before the internet was really big. I use to use this company to exchange my genesis and snes games for other games.
I believe I originally found them advertized in a magazine like EGM. You could call them and request an updated list.
They mailed it out and the list of Genesis /Super Nintendo games were ranked in sections
A titles
B titles
C titles
You would find your game on the list. Lets say it was an A title. You can then select and exchange your A Title for any other game in the A title.
You would fill out your info form on the sheet and mail your game and a check for the exchange fee (maybe 10.00 an exchange).
About 2 weeks later your game would be in your mail box.
I remember I used them several times and never had a problem.
Does this sound familar to anyone?