My take was...For folks who like phone shops, it seems some MSCs offer shoppers the opportunity to join a "call team." Being on a team offers stable work and income each month. The OP just found out about this revenue stream and kindly is informing others who may not be aware. OP hit the nail on the head with that one.
There was an analogy to route shopping perhaps because the calls need to be planned out and completed over several days.
Further, 2 posters confirmed they are/were part of a call team. One likes it; one didn't.