The racecard may cost a little to produce, but I would assume that it also creates revenue from the advertisements on it (possibly leaving the management in profit).
On the website today, encouraging the purchase of season tickets, the link to the page giving information clearly states a racecard is included whether you have a season ticket, or pay on the day.
Can anyone confirm, but I seem to remember, several years ago there was a monthly magazine on sale at the track shop.