The salary of a copywriter depends entirely on two things:
1. Geographic location (rural vs. major city)
2. The type of company (large agency? small corporation?)
Copywriters are divided into three categories:
The salary for a just-starting-out junior copywriter could be $25,000 to $32,000 or so. For a copywriter, perhaps $32,000 to $45,000. For a senior copywriter, anywhere from $35,000 to $95,000 depending on the criteria noted above (geographic location and company size/type).
In an agency, the next step up from copywriter is Associate Creative Director. After that, Creative Director. Then VP. Agencies tend to pay more than corporations.