The phrase, "What's the deal with..." is so synonymous with a specific brand of '90s observational comedy, I bet you just read those words in Jerry Seinfeld's voice. Ask someone to do a impersonation of the comedian (don't actually do this), and they'll assuredly whine, "What's the deal with..." before either trailing off or mentioning some quotidian subject of scorn. It's funny because he always said it! Or did he?
After searching through the scripts for every episode of Seinfeld, the phrase, "What's the deal with..." was never used sincerely (i.e. said in the context of genuine observational humor) during the show's entire run, including all the pre-intro stand-up sets.
The closest the series comes is during the season two episode "The Deal," and Jerry doesn't even say it. At Monk's, George asks Jerry, "What's the deal with Aquaman? Could he go on land, or was he just restricted to water?" before they change subjects and venture into a conversation about Jerry sleeping with Elaine.
The phrase wouldn't be said again in the series for another five years, and from that point forward, all instances of "What's the deal with..." are self-referential and used to make fun of the hokey phrase. In all, and not including "The Deal," it's only said in five of Seinfeld's 180 episodes:
1. "The Invitations," Season 7, Episode 24
Jerry decides his fiancé Jeannie (played by Janeane Garofalo) is too similar to himself after she uses the hackneyed joke structure twice:
Jerry: Well it's been quite a night. I could sure use a cup of coffee.
Jeannie: Hey! What's the deal with decaf? How do they get the caffeine out of there, and then where does it go?
Jerry: I dunno.
...
Jerry: (to the waitress): I' ll just have a cup of coffee.
Jeannie: Bowl of corn flakes.
Jerry: More cereal? That's your third bowl today, you had it for breakfast and lunch.
Jeannie: Hey! So what's the deal with brunch? I mean, if it's a combination of breakfast and lunch, how comes there's no lupper or no linner?
Turned off by this, Jerry cancels the engagement.
2. "The Abstinence," Season 8, Episode 9
Jerry bombs at his former junior high school with, "Hey kids. What's the deal with homework? You're not working on your home!"
3. "The Summer of George," Season 8, Episode 22
George pitches a joke to Jerry for use at the Tony Awards—"What's the deal with those guys down in the pit?"—which Jerry rejects: "They're musicians. That's not a joke." Later, when deciding between playing frisbee golf and going to see Jerry, George imagines Seinfeld delivering the stale gag, "What's the deal with airplane peanuts?"
4. "The Butter Shave" Season 9, Episode 1
Jerry sabotages his own act to prevent hack comedian Kenny Bania from riding his coattails:
Jerry: What's the deal with lampshades? I mean, if it's a lamp, why do you want shade? And what's with people getting sick?
...
Jerry: I mean, what's the deal with cancer?
Audience Member: I have cancer!
Kramer: Oh, tough crowd.
5. "The Finale," Season 9, Episode 24
The series ends with Jerry doing a failed set at the prison where he and the gang are serving time:
"So, what's the deal with the yard? I mean, when I was a kid my mother wanted me to play in the yard. But of course she didn't have to worry about my next door neighbor Tommy sticking a shiv in my thigh. And what's with the lockdown? Why do we have to be locked in our cells? Are we that bad that we have to be sent to prison, in prison? You would think the weightlifting and the sodomy is enough. So, anyone from Cellblock D?"
Seinfeld routinely made fun of tired sitcom tropes, so it's no surprise that they went after his would-be catchphrase. Still, it would seem that somewhere between 1991's "The Deal" and 1996's "The Invitations," What's the deal with... became prevalent enough to co-opt. According to Google, the phrase's appearance in magazines and books rose exponentially starting around the show's premier before it leveled out in the mid-2000s (the show ended in 1998).
Beyond searching through old episodes of Seinfeld, I couldn't find evidence of him using the phrase in televised stand-up appearances, either. One place I was able to find it was in his 1993 book of quips and jokes, SeinLanguage. In it, there is only one instance of "What the deal with...":
Can someone please tell me what is the deal with B.O.? Why do we need B.O.? Everything in nature has a function, a purpose, except B.O. Doesn't make any sense. Do something good—hard work, exercise—smell very bad. This is the way the human being is designed. You move, you stink.
So, beyond that example, before he started making fun of it on his own show, Jerry Seinfeld's oeuvre is pretty much completely devoid of the phrase "What's the Deal With...". This raises the question: Who started saying it?
The answer is...Jerry Seinfeld (gasps fill the auditorium).
The culprit appears to be a 1992 Saturday Night Live episode hosted by Seinfeld himself. In a sketch called "Stand-Up and Win," he plays the host of a game show where lame comedians answer questions like, "What's the Deal with Airplane Food?," "What's the Deal With the Black Box?," "What's the Deal With Count Chocula?," and so on and so on.
Naturally, he was in on the joke from the very beginning. Despite this, "What's the deal with..." is still being used by hack headline writers to this very day, including yours truly.