Like a giant, digital scratch 'n sniff, there is an outdoor campaign in England for McCain's "ready baked jackets" that emits the smell to entice consumers.
At bus stops, users can push a button and a light will 'heat up' a large image of a potato and produce the delicious smell, and a coupon for the product. Created by JCDecaux, posterscope, and BMB Creative.
Yum. If you like potatoes, that is. (And yes, there are people out there who don't.)