Every mall in America survives because of what are called "anchor stores." Usually big box department stores like Foley's, Nordstrom's, and J.C. Penney, anchor stores account for the bulk of foot trafficand resultant businessmalls receive.
Last week marks for me my third "anchor client." All three have enough copywriting business to keep me very busy.
The trick is to continually and gradually raise my fees. If one of my clients decides they no longer want to pay my rates, it will be relatively simple to find another client or two to fill the hole.
Keep this in mind: if you can find three anchor clients, you'll quickly be earning enough to support yourself as a full-time copywriter.