WWE executives were asked about the revenue generated by The Greatest Royal Rumble event during today's Q2 earnings call, but they would not speak on specifics citing confidentiality agreements. Using the data from today's Q2 earnings report, the event could have brought in somewhere in the neighborhood of $40 - $50 million for the company.
Dave Meltzer noted on Wrestling Observer Live that the revenue from the event would have been included in the "Other" portion of the revenues listed in today's earnings report. The revenue for the first three months of 2018, ending June 30th, was listed at $60.6 million. This up $48.7 million from the $11.9 million from the same period in 2017. This does not mean the total increase is from the event, however it is safe to assume that WWE generated $40 - $50 million from the Saudis for the event.
The Greatest Royal Rumble was the first event held under a new 10 year partnership with the Kingdom of Saudi Arabia. It was noted during today's call that the 10 year deal will include more events like GRR but they are still working on the timing of the next show. The event held back in late April from Jeddah, Saudi Arabia played a big part in the success of the quarter.