Residential Property Management - How Much Should I Spend on Marketing?

Marketing, I refer to marketing as the great black art. There's just not a formula, but there are patterns of things that work. The vast majority of businesses grow through their P&L by diminishing current profitability and then getting somewhere else in the future. Is the market allowing me to be profitable at the moment? And if you're an operating agent who is making the living with costs for your business, do you really want to run it right now?