DETROIT — After you have spent a very pleasant evening in a shiny new sports arena in a spruced-up neighborhood in a once-decaying city, it feels unduly meanspirited to mention that the place feels kind of empty.

But that has been the vexing situation lately in Detroit, where the enormous fanfare that greeted the opening of the Little Caesars Arena in September has been followed by a succession of not-so-enormous basketball crowds.

Though the Detroit Pistons’ first home game was announced as a near sellout, with 20,491 seats sold, many of the people who supposedly paid for the seats appeared not to be sitting in them during the actual game. The Pistons were 26th in the N.B.A. in home attendance through Thursday, with an average of 16,214 for their first six games at the new arena.