** Discontinuous: There is no reason to believe something special happens 4 days after a visit.
* '''Performance'''
** It requires periodic recomputation, which I believe currently happens during an idle.*** Idle-daily eventrecomputation already uses exponential decay (implemented in {{bug|476299}})*** On-visit recomputation does not use exponential decay.
* '''Memory, privacy'''
** The algorithm requires storing storing details about multiple visits.