In 2025, Manhattan Beach listing descriptions suddenly exploded with em-dashes – 129 of them in just six months’ worth of local listings. That’s nearly three times the total from the prior three years combined.
And 87% of those dashes appeared exactly the way ChatGPT writes them: With no spaces on either side.
The numbers don’t lie. Realtors are leaning on A.I. to do their writing.
Why? Real estate is a marketing job, but not everyone in the field is comfortable producing words. Listing descriptions can be awkward, even cringe.
ChatGPT and similar A.I. services have changed that, offering agents a quick fix – often producing text that looks polished. (Hey, one might even argue that this is a nice improvement!)
How do we know this is happening? There's a big tell: The em-dash.
What’s an Em-dash?
The em-dash (sometimes “m-dash”) is a punctuation mark that is wider than a hyphen by a good measure. The character is obscure enough that you may or may not know how to generate one on your own keyboard.
Here’s how various forms of dashes look:
Hyphen: -
en-dash: –
em-dash: —
The em-dash is named for its width, equal to a capital M in a given font. It can function like parentheses or a semicolon, helping to set off a thought or a sentence branch – everyone has a different style.
Should there be spaces on either side of an em-dash? This is a critical question for what we’ll be discussing next.
Some formal style guides, like the Chicago Manual of Style, call for no spaces—none at all—with an em-dash. (See how weird it looks?) Most newspapers and magazines use Associated Press (AP) style, which calls for spaces.
Use of the Em-dash = ChatGPT
The em-dash with no spaces is a quirky hallmark of text produced by ChatGPT.
If you know, you know. It’s just been their style.
OpenAI made this into big news in the past week, announcing that users can now change a setting in ChatGPT to purge the use of em-dashes. They know that people have not been adopting the Chicago Manual en masse, but they have been getting caught publishing unedited ChatGPT text.
Get rid of the em-dashes, and you might disguise your use of A.I.
But for some listings, it’s too late.
Statistics Don’t Lie
Recently, we went briefly mad, suddenly feeling like we were seeing ChatGPT text in almost every new listing description in town.
But maybe we were wrong? Had we just missed the meeting where everyone agreed to use Chicago style from now on?
We like to answer questions with data. So, here goes.
We looked at 6 months’ worth of home sales over the same period (May 1-Oct. 31) across several different years (2010, 2019 and 2022-25).
We searched all of the home descriptions, looking for em-dashes.
In 2010, there were none used in 219 listing descriptions.
In 2023, there were 9 in 148 listings.
Last year, double that, a whopping 18 in 178 listings.
Here in 2025, we found 129 em-dashes used in fewer listings (167) sold over 6 months.
Of those, 112 em-dashes (87%) had no spaces on either side, the way ChatGPT often provides text.
Those 129 em-dashes were nearly 3 times the total number of em-dashes used in 515 listings we sampled over 3 years from 2022-24, and more than 7 times last year's total.
Conclusion: The em-dash was everywhere all of a sudden this year – because ChatGPT was, too.
It's Not Just Em-dashes
We found other quirks that seem like telltale signs that agents are publishing ChatGPT product without much editing.
Among all the 2025 listings we examined, 22 followed an em-dash with the word “perfect,” as in, “—perfect for gathering friends and family for a meal.” Another 14 cases used the word “ideal” right after an em-dash.
We checked prior years' listing descriptions, and among the 5 other years we studied in detail, there were a total of 3 instances of “—perfect” and zero instances of “—ideal.” These are almost purely 2025 phrasings!
We also found 4 instances this year of listings saying in almost the same words, “it’s not just a home—it’s a lifestyle.” (Sometimes without an em-dash.) Before this year? Zero.
The more of these descriptions you see, the more you see the same basic "thoughts" repeated. Could be A.I., could be the Realtor hivemind, could be ancient real estate clichés. Probably a mix.
But mostly, we're lookin' at you, GPT.
Em-dash Methodology
Dear reader, we don’t want you to just have to take our word for this. Here’s how we got our data.
We asked ChatGPT to write a Python script for us to…
No, haha, we did not do that.
This was actually simple enough to do “by hand” with clever use of spreadsheets and a couple of word processor docs.
First we exported MLS data for 6 months’ worth of sales – May 1 through Oct. 31 for each year studied – and copied all of the descriptions into files that we could search. Counting was quick once set up. (Coffee was involved.) Then we just tallied everything in a spreadsheet.
Oh, for what it’s worth, here at MBC, we really don’t use the formal em-dash character, although we do use en-dashes in the way most writing nerds prescribe em-dashes. We think the actual em-dash is just too wide. And we always use spaces. Also, our posts and listing descriptions are not written by A.I.
So here’s the question: Will 2026 see more em-dashes? Will agents be turning away from ChatGPT, or turning off the em-dashes, or at least trying to do a better job disguising that they got help with their work from bots?
Psssst! Don’t tell anyone we’re on to them. We’ll study this again next year!
