Even the premise of the original Paranormal Activity films was nothing really new - the effects of demon possession captured for all to see on a suburban family's in-house security camera footage. But the difference is that it was done well - although there was almost nothing new in it, there was no arguing that the nocturnal camera footage of a silent and still average family home was undeniably creepy. And then, when things began to turn pear-shaped, and the silence was suddenly shattered, the "jump-in-your-seat" moments were custom-built to make the most of the modern cinema experience.
Because of this, the Paranormal Activity films have always suffered in translation to DVD and television screens.
Paranormal Activity 3 has plenty of creepy moments, and plenty of sudden frights designed to get the blood pumping.
But after about 180 minutes of this in the previous two films, there's not enough new material here to justify another sequel - or, more accurately, prequel.