Traditionally, real estate sales have peaked in spring, making it the optimal time to sell. The popularity of spring home sales once had a lot to do with buyers wanting to time a move around the kids' school schedules. Today's buyers are different, though. Many of them do not have children in school and so they're less likely to wait for spring to make a move. In this new market, a savvy seller knows that a house is more likely to sell fast when inventory is low, as in the cold months from November through January.