Irritating Quote of the Week

From a really, really irritating Sensodyne advert, in which some pretty pictures demonstrate toothpaste sealing up holes in teeth, comes one of the most worryingly illiterate sentences I've heard in quite a long time:

We've clinically proven it works, but we really know it works because people keep coming back time and time again.

Seriously? They have the gall to put someone in a white coat in their advert then come out with such utter nonsense? I wish I had sensitive teeth so I could refuse to by Sensodyne on principal.