Who did the promoters get to star in the massive advertising campaign for the Pegasus World Cup? Conor McGregor.YouTube

It’s the biggest horse race in history with the largest ever purse, $12 million to be exact, and it will be run before a packed house on January 28 at Gulfstream Park in Florida and a national television audience on NBC.

So who did the promoters get to star in the massive advertising campaign for the Pegasus World Cup? A famous jockey? An incredible trainer? A wealthy billionaire owner?

No, it is Irishman Conor McGregor, king of kings in MMA and now king of the turf as he does the major promotion for horse racing’s biggest day. It is an example of what a huge brand he has become.

The plot line in the ad is simple. The Irishman had destroyed everything in front of him at MMA so he can do the same in horse racing by riding the winner of the Pegasus.

Slight problem, which the Pegasus promotion does not make clear: McGregor, at 154 pounds, is about 40 pounds heavier than the average jockey.

Now he may box great, and kick great and wrestle great, but there is no chance on earth he can give 40 pounds away to his rivals. He’s Minnesota Fats to Slim Pickens, Fatty Arbuckle (look him up) to Slim Whitman (look him up too).

Two of the greatest horses, perhaps of all time, are favorites for the Pegasus. There’s California Chrome, the rags-to-riches superstar who cost $10,000 and now has won over $14.5 million, most of any racehorse ever.

California Chrome.

California Chrome.

After this race Chrome is off to stud and just in time too. He has taken to acting “studly” in the parade ring before races, to use that quaint old phrase – it’s time he met some fillies.

Then there's the Bob Baffert upstart, Arrogate, a horse which only began to shine in late Autumn last year but who ran down Chrome in the Breeders Cup Classic, up to now America's greatest and richest race.

McGregor fits in as a winner and a wit to boot and the advertising for the big day sparkles as a result. The final two shots have him on a horse being led round and round a walking ring.

Come Pegasus day on January 28 he should be walking on air if the massive crowds show up.

The purse is raised by charging $1 million to enter. Maybe McGregor can enter and flatten the opposition jockeys before the gate opens.

Either way he's on a winner as his reputation just grows and grows. As renowned racing scribe Damon Runyon once said “Rub up against money/ ..sooner or later it will rub up against you.”

Conor McGregor is on his way to being one of the richest athletes in sport by doing that.

Read more: Nine amazing quotes from Conor McGregor