First it was Jimmy Kimmel declaring his love for Jimmy Fallon. Then it was the Yankees being nice to the Red Sox, which was almost unfathomable, yet also understandable and gracious in the wake of the Boston bombings. But now it's getting out of hand: Arch-rival corporate brands are being nice to each other with no discernible provocation whatsoever.
Earlier this week, a bunch of British snack brands, from Cadbury to Walker's Crisps to Jaffa Cakes and Phileas Fogg, threw each other a veritable Twitter Tea Party -- and indeed, Yorkshire Tea joined in the lovefest.
And last week, Microsoft's Xbox One team engaged in a random tweet of kindness toward the Sony PlayStation 4, even though the two products are about to go head-to-head in a high-stakes holiday-shopping-season showdown that will help shape the fates of both companies for years to come.
What's next? A Ford F-150 ad congratulating Chevy on the 2014 Silverado? McDonald's congratulating Burger King on putting its Big King back on the menu? Hertz admitting that Avis really does try harder?
The surprising thing is that, whether genuine or cynical, Microsoft's gesture seemed to work: It's been retweeted some 15,000 times, ensuring that the PS4's launch doesn't entirely overshadow the upcoming launch of the Xbox One in terms of social-media buzz this week. I predict that, as with Oreo's timely Super Bowl tweet, Microsoft's olive-branch ploy will become a trend among the savvier brands on social media, which will compete to garner goodwill by saying nice things about their arch-rivals.
That doesn't sound like a bad thing, on its face, although I could see it turning from sweet to saccharine rather quickly. And, of course, there's a shelf life built into any trend of this sort: Once it becomes the norm, it will cease to surprise, at which point perhaps everyone will go back to being mean again. Which can, of course, be pretty delightful in its own right.
• Oremus is the lead blogger for Slate's Future Tense, reporting on emerging technologies, tech policy and digital culture.