See one get one free - on all art experiences!
Idea: Cover as many gallery windows as possible with big SALE signs and give each visitor as he/she enters a shopping basket. Sale signs & baskets will create link between the high street and the gallery, as shopping (and sales!) is a common experience.
During the walk around the gallery people will not be able to fill their baskets with any objects (apart from purchases from the shop), however internal spaces of gallery (corridors/ entrances to the exhibition spaces, toilets, lifts) will be filled with advert like signs saying: See great art & think about it! Clean your hands & soul! Etc.