It's inexpensive, it allows you to carefully target your customers, and it's big time media. Radio never closes and never rests. That's great news for you. Compliment them on their work. Tell them how much you like their radio station.
Fans get on the air for free.
If at first you don't succeed, try again with different stations and personnel. Just about every kind of business uses brochures. Brochures say to the world that you are in business and serious about what you're doing. In some fields, the brochure is a door opener. Clients won't even consider doing business unless you first present them with your brochure.