$904 million is the revenue in the industry per year. Valuation is the "present value" of all future revenue, i.e. what all of the profits the company is "expected" to ever make are worth today.
To give an example, if I were to give you $100 every year for all of time, you would certainly pay more than $100 today. Maybe even $500. And if I were to say I would give you $100 the first year, then 10% more every year such that you'd get 100, 110, 121, 133.10, etc... you should be willing to pay a lot more because in 30 years you'd be getting $1700 / year and growing.
That's why businesses that are expected to make money for a long time are worth a lot, and those who are expected to last a long time and make an increasing amount of money every year are worth so much more today.