Nissan managed to release an ad just seven minutes after the announcement, promoting the Nissan X-Trail seven seater.
Other brands weren't far behind with messages of congratulation on Twitter, including John Lewis, WKD, Innocent and Morrisons.
These on-the-fly responses are prime examples of the "social newsroom", a growing trend where brands ditch long-term planning for spontaneous reaction to the news. In this case, some managed to have more panache than others, with congratulatory messages ranging from the restrained to the positively lewd.
— Morrisons (@Morrisons) September 8, 2014
Congratulations to the Duke and Duchess of Cambridge! We've got a fair few buns in the oven too – at our bakeries of course! #RoyalBaby
Delighted to hear the news from @ClarenceHouse that The Duke & Duchess of Cambridge are expecting a second child - congratulations!— John Lewis (@johnlewisretail) September 8, 2014
KATE MIDDLETON IS PREGNANT. KEEP CALM, EVERYONE. KEEP CALM.— innocent drinks (@innocentdrinks) September 8, 2014
Some brands were decidedly unimaginative.
Others tried to imitate Nissan to produce ads or content at speed. That strategy backfired for WKD, which was roundly mocked for misspelling "Middleton" in its tweet.
— WKD (@WKDOfficial) September 8, 2014
@WKDOfficial you've got some wkd spelling— Jennifer Hassan (@GuinnessKebab) September 8, 2014
Clothing and baby brands went for sheer opportunism.
Congrats on #RoyalBaby number 2! It’s going to be double duty diapers for you.— Pampers (@Pampers) September 8, 2014
Did you see any great (or awful) examples of brands jumping on the royal baby bandwagon? Let us know in the comments or tweet @MarketingUK.