LORELAI: I just wanted to tell you how amazing you were tonight. Really, you completely came through for her.
CHRISTOPHER: She deserves it.
LORELAI: I haven’t always given you a lot of credit in the past, but I’m giving you credit now. Big credit. Major credit. Buy yourself a sofa.
Lorelai is referring to store promotions, common for big ticket items such as furniture, where credit is extended to approved customers so they can take their purchase home immediately.