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. But now it’s getting out of hand: Arch-rival corporate brands are being nice to each other on Twitter with no discernible provocation whatsoever.

Last month, Microsoft’s Xbox One team engaged in a random tweet of kindness toward the Sony Playstation 4, even though the two products are going head-to-head in a high-stakes holiday-shopping-season showdown that will 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 about 23,000 times. Should we 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 these types of things can turn 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 everyone will go back to being mean again.

Which can, of course, be pretty delightful in its own right. □