It is my understanding that the Guinness Book Of World Records was started because of a discussion/argument in a pub that had no resolution, a couple of blimey blokes fussing about what's the longest bridge in the world or something, so publishing a book of world records would allow that kind of thing to be settled. It then became a marketing gimmick; people start mentioning Guinness in contexts they never would otherwise. The book itself has been a sales phenomenon, and then they started selling the records themselves.

So...Guinness sells the service of awarding a world record, sometimes at exorbitant prices, and often to brutal dictators. The likes of North Korea, Qatar etc. are fond of these. Kim Sick Fuck will order 90,000 people to dance at gunpoint and Guinness will send a white chick in a stuffy blue skirt suit with a framed certificate, for tens of thousands of euro, to certify it as World's Largest Interpretive Dance.

I wonder if they make more money doing that or selling Bud Dark?

Edit to add, off the top of my head I can think of the Guinness World Record book being mentioned offhand in media as diverse as Happy Days, The Brady Bunch, House and The Abyss, among others.