Less Inventory = Less Competition
Fewer homes are listed in the winter and lower inventory means more seller control. Since buyers don't have a glut of winter homes to view, you have a better chance to sell your winter listing for top dollar.
People willing to brave the cold and snow to look at your home are serious about buying. You might have fewer showings, but the people who take time to tour your winter listing are typically motivated, qualified buyers.
Less Worry about Curb Appeal
Curb appeal is always important, but in the winter you don't have to worry about meticulous flower beds, groomed lawns, swept patios, etc. It is often a lot less work to sell your home in the winter. Shovel your sidewalks, and you are ready to show!