All these looks and not one reply? All right, I'll bite. Forgive the cliches, but Christians aren't perfect, just forgiven. As in all good business, I suggest that you don't trust anybody. Not to justify it, but some who call themselves Christian have no problem whatsoever separating business from "religion."
To target the demographic, purpose to associate with it. Hang out at church social events. Forget the big national accounts, or at least expect much fewer opportunities. Depending on where you live, consider potential clients more like Country music-types or southerners: since northerners (like me) are much more impolite, we will save you time by getting to a "No" more quickly. Remember the erroneous (at times) notion that advertising automatically impacts immediately: explain how the planting of seeds takes time, and give realistic goals and expectations. Win them, then they'll win you friends. Burn them (intentionally or not), and they will have difficulty not trashing your reputation. When you become a part of the fabric of the listening community, they will come to you. Network, network, network: the people you sold Saturns to years ago (print) may be interested to know that now you're with Land Rover (radio).
Befriend your airstaff, treat your support staff like gold (in traffic especially). Invite your Production Director-types to weekly sales meetings, asking for a weekly spec spot for a generic business (restaurant, car dealer, etc.). Hook them up with restaurant vouchers and theatre tickets, they tend to make dirt compared to salespeople. Get their input, and give them plenty of time to do great work. Few things tick us off as much as banging out an unnecessarily rushed hack production job, when we could have done something special with it. Don't think that what works in print automatically translates into radio. If you write your own spots, balance "theatre of the mind" with "repetition, repetition, repetition."
I'll invite the opposition to present its case against this: Your job is business, not ministry. How you act in everyday life is ministry. I have met many men and women "on a mission," "happy to work in a Christian environment," etc., who were simply not good at their jobs. In secular and Christian radio, I have forgotten the names of countless salespeople who have not made the cut. I also know a very select few whose walks inspire me, whether or not their numbers were good. Be above reproach, and God bless your endeavors (Proverbs 29:11-13).
From waking until sleeping you are in some way serving someone, the only questions are who and how well. Your clients will be able to tell even before you ever get a chance to say Jesus' Name.