My sales are up for January, but I attribute that to my guilting of my membership on the free side of my site (Start the New Year off right, support this site!)
Traditionally, January is a slow sales month for all forms of business. Why should porn be any different? Heck, how many men are still pretending they gave up porn and masturbation as a new years resolution?
Wait a month. Let them by alone on Valentine's day and they'll come back to their real love... porn.