Definition: A 'bench marketer' is a sales person at a staffing or consulting company that is responsible for marketing that company's consultants that are not working on projects to potential clients.
Staffing and consulting companies have a roster of consultants on their payroll that switch in and out of projects at clients. When these consultants come off a project and there is no immediate next project for them to work on, they are said to be 'on the bench' like 'extras' on a sports team. The staffing company is interested in getting them onto billable projects as soon as possible and so they employ 'bench marketers' whose job is to advertise these consultant's resumes on job boards and local freelancer marketplaces, apply to jobs posted, solicit enquiries, arrange interviews, negotiate rates with potential clients.
The difference between a 'bench marketer' and a typical staffing agency sales person is that the bench marketer has a consultant that is ready to start work and is looking for job/requirement to place them. A staffing agency on the other hand first looks for jobs/requirements with a client and then goes looking for a consultant to fill that role. Since these are slightly complementary, oftentimes bench marketers focus their sales on other staffing agencies that have existing clients or lots of open requirements. If a deal if finalized where a bench marketer finds a job opening for one of their consultants through another staffing agency, they would sign a Corp-Corp contract which is basically a subcontracting agreement. The 'bench marketing' company continues to run the payroll for the consultant, but the consultant now works through the client staffing agency at the end client's work site.
Most of these consultants are usually on the staffing agency's payroll (w2 salaried employee) or the staffing company may have sponsored the consultant for an H1B visa sponsor or an L1 visa. Often times these consultants could also just be under and informal contract or with an understanding that they can represent them to clients if they believe the staffing agency can work as a talent agency for them as they have a better network of contacts with recruiters and staffing agencies and better knowledge of the market. On the downside, the introduction of an additional 'layer' tends to reduce the net billing rate the consultant may make.