This episode was actually based on a true story. In real life, Jerry Seinfeld's accountant stole money (about $50,000) from him to buy drugs, thus inspiring the main plotline for this episode.
"My accountant, whose name I won’t mention (not that he doesn’t deserve the infamy) stole I think fifty thousand dollars from me, and snorted it up his nose...[I] just gave him an envelope of cash, and never saw it again. And I used to talk about that guy and how much I hated him, so he became the Sniffing Accountant. That was some measure of revenge."