It is probably not the agent. If it is listed in the MLS you are getting enough viewers. Problem probably is the price. Why else would people not buy it? New agent will do cartwheels and get a buyer? Check out some post in here and you can find investors listing at a loss. Markets not hot anymore.
But I REALLY would check into SD Realtor (not sdrealtor) in this forum. His views on the market are sound and will probably get you’re place sold .