Most people know how to market but not everyone knows how to market effectively. When you mail a prospective client a piece of your promotional material advertising your availability as a commercial copywriter who is seeking work and don't get a response, then that's marketing. But when the prospective client responds to your promotional material and requests additional information that leads up to work, then that's marketing effectively. Marketing is probably the most ignored and neglected function of operating a profitable commercial copywriting business. Instead of working eight hours each day for clients, you really work five or six hours each day for clients.
Marketing is non-billable time.
When a freelancer stops working on his client's project to do his own marketing, he does not get paid for his time. Marketing costs money and can exhaust your time. A popular complaint among freelancers is the lack of time to shoehorn daily marketing into their daily schedules. Working on lengthy projects, meeting deadlines, keeping in touch with clients and managing a business can place a lot of strain on the writer. Beginners often quit their marketing efforts too soon because they're not soliciting responses immediately.