Shareholder update - goodbye GSK toothbrush?, page-93

Probably because market research has told GSK that the average time people take to brush their teeth is around the 30 seconds mark so that becomes their target. If they have found that it takes well over the mark to achieve optimal results, then there is no point releasing a product of which the majority of users will see little to no benefit.

I'm sure both GSK and OBJ have been working tirelessly to tweak the product but at the end of the day the 30 second target just was not achievable.