Real estate agents see it all.

From the unmade beds to the overstuffed garages to the “What were they thinking?” decor. Over the years, they learn a thing or two: Why some houses sell, while others linger on the market. Why some promising buyers never make it to the closing table. How to get a better deal on the mortgage. Even just how much the other agents stand to make on your home. And the good news is, they want to share. Whether you’re a buyer, seller or both, here are six things real estate agents wish you already knew.