“Just Say ‘No'” — Home Seller Version
If serious home Buyers (and their Realtors) usually plan their showings well in advance, it’s a good rule of thumb that last-minute showing requests are typically . . . just curious. See, “Dealing with Emergency Showings.”
Which is why I give home Sellers I represent permission to say “No,” especially if accommodating the showing means disrupting a family meal, doing somersaults to get their home ready in 30 minutes (or less), etc.
That’s especially true around the holidays, when people are entertaining, hosting guests, etc.
In my experience, if the Buyer is really serious, they’ll double back with more notice.
Getting in the Door
So, my eyebrows went (way) up when I received a short notice showing request (less than 2 hours) earlier this week, coupled with the heads up that it was a “third showing.”
Vaguely remembering the Realtor, I did a search of the listing’s showing history, and found that the agent had in fact showed the home six weeks ago . . . but that was it (no follow-up, conversation(s) with the agent, etc.).
What happened next?
My client declined the showing — coupled with an invitation to reschedule with more notice — and that was the last they heard.
Best guess: the prospective Buyer was already looking at something in 
the neighborhood, and wanted to see my client’s home as well.
Contrast With Relocation Buyers
Whereas it’s appropriate to deflect such “serendipitous” showing requests, the opposite tack is appropriate with relocation Buyers.
Such Buyers are known for being: a) motivated; b) financially well-qualified; and c) under acute time constraints.
For all those reasons, would-be Sellers are well-advised to accommodate such Buyers whenever it’s reasonably possible.
However, precisely because of attributes “a.,” “b.”, and “c.”, agents working with relocation Buyers usually take pains to preview and/or schedule showings well in advance.
When that’s not possible, they’re proactive about contacting listing agents to arrange last-minute showings and explaining the circumstances.
When Showings Are Never Convenient
Of course, at the other end of the continuum, there are would-be(?) home sellers for whom showing requests are never convenient, and habitually decline them.
That, as they say, is “a horse of a different color.”
When that’s the case, accommodating showings is usually the least of the Seller’s problems
Translation: price, condition, marketing, and staging — or lack thereof — typically loom larger.
