What does the demand number mean?

It is passengers a day for that city pair, both directions together, before anybody competes for them. A pair showing 600 is roughly 300 each way.

It is the market, not your share of it. What you actually win depends on your fare against the recommended one, your reputation, and who else flies the sector.

It moves through the year — see seasons — and it grows about 4% a year, the same for everybody.