You're asking strangers to give you their money in exchange for something you have. It won't happen until they trust that your product or service will do what you say. Repetition leads to familiarity, which leads to trust, which leads to prospects becoming customers. In general, it takes a minimum of four repetitions before a message is effective. As your business grows, you can increase your advertising and prospect for new customers in other media.
Successful advertising attracts more than customers-it also draws salespeople.
Each will present a convincing story of why you should advertise with them. Listen politely, but be firm in refusing if it's not a medium you think will work for you or if you don't have the budget to make it work. Put the audience in your story. Speak to your prospects' self-interests. Your message is about their needs, not yours.