Proffesional theatres obviously have more money and can advertise in papers. Advertising Equally important to filling the show up is selling advertising space in your show program. There are two ways of selling ads. First is directly selling them by gowing to local retailers and offering them space. Usually space is sold as a page, half page and quarter page incriments.
Prices can go according to the production overhead, but remember, advertisers are paying to be seen.
The longer your show run and larger the theatre, the more they are willing to pay for space. The second way of selling ads is through trading. Perhaps you need paint. Trading for space in other theatre's programs works too. This is perhaps the easiest way to raise money for a theatre.