Impulse at the Self-Scan ?

Coles, Broadway. I was interested to see impulse product lines at these checkouts.  They do, however, seem to be an afterthought.  I would imagine that shoppers will need to get used to the mechanics of using these machines before they will have the 'head space' to pay attention to impulse items.  Having said that, it made me wonder whether in doing away with the traditional express checkouts, supermarket operators have factored  in the loss of sales on impulse lines ?