The valuations below (except where stated otherwise) are taken from the latest Brand Finance Global 500 Study, released this week, and we've used the enterprise value figure, which is in essence a theoretical takeover price. Of course, there's no way of knowing exactly what a company would cost after negotiations, but this is probably about the best estimate.
While this is just a bit of fun, it does show how far WhatsApp has come since it was founded in 2009. It has just 55 staff, and it's already valued more highly than some of these giants...
Netflix enterprise value: $14.673bn
Facebook could have acquired Netflix and had spare change for popcorn.
Royal Mail enterprise value: $11.036bn
A different kind of messaging service, granted, but the UK's postal service is well within the reach of Facebook - and it was available for a cut-price £3.3bn when it was floated in October. Pocket money.
Ferrari enterprise value: $6.03bn
Mark Zuckerberg could help himself not just to a sports car, but the whole fleet.
ITV enterprise value: $8.46bn (*according to Stockopedia)
Britain's main commercial broadcaster was established in 1955; WhatsApp was founded in 2009.
Burberry enterprise value: $10.598bn
The luxury British fashion house would be a steal at almost half the price of WhatsApp.
Heineken enterprise value: $11.857bn
Why by a beer if you can buy the brewery?
Marks and Spencer enterprise value: $15.455bn
British retailer has 703 stores in the United Kingdom and 361 stores spread across more than 40 countries.
Louis Vuitton enterprise value: $18.398bn
Luxury French fashion house had a 155-year head start on WhatsApp.
Audi enterprise value: $17.731bn
German automotive firm Audi has nine production facilities in eight countries.
American Airlines enterprise value: $10.666bn
Forget the cars, Facebook could buy an entire airline for less than WhatsApp.
Johnnie Walker enterprise value: $18.843bn
Owned by Diageo, Johnnie Walker enjoys yearly sales of over 130m bottles.
Tiffany & Co enterprise value: $12.079bn
A global icon, Tiffany & Co markets itself as the world's premier jeweller.
KFC enterprise value: $19.492bn
This would push the budget slightly at just over $19bn, but with some good negotiation it would be within Zuckerberg and co's grasp.
Sainsburys enterprise value: $15.026bn
The third largest chain of supermarkets in the United Kingdom.
Nivea enterprise value: $16.155bn
Global skin and bodycare brand headquarted in Germany.
Sharp enterprise value: $14.973bn
Japanese electronics giant employed 55,580 people worldwide as of June 2011. That's about 55,525 more than $19bn WhatsApp.
Omega enterprise value: $10.337bn
Luxury Switch watchmaker's products have adorned the wrists of John F. Kennedy, Buzz Aldrin and James Bond.
Kraft enterprise value: $17.151bn
US grocery giant formed in 2012 by a demerger from Kraft Foods Inc.
Duracell enterprise value $9.755bn
Zuckerberg could have added power to his business with the acqusition of Procter & Gamble brand Duracell.For more detailed analysis of the WhatsApp deal, you should read our round-up of industry reaction from marketing luminaries such as Sir Martin Sorrell and a host of digital agency heads.