When You Speak To Everyone, You Speak To No One
This quote basically says that if you are marketing to everyone, then your message will be so generic that you are not appealing to anyone. Nobody will feel spoken to and no one is going to hear you.
You need to personalise your marketing messages. You can only do this if you are clear on your target market and on your ideal client. Know what their urgent needs and compelling desires are.
Then communicate in THEIR language how you can help solve their problems.