You know how it is: you park your vehicle in a crowded parking lot and are worried about finding it when you leave. The answer is to take a picture of the space number with your phone. A Romanian bookstore chain used this tactic to its advantage. In the car park of a large shopping centre, it placed a poster with the title of a book and a money-off barcode below each location panel. Arriving at the bookstore in the shopping centre, customers who’d taken a snap scanned the barcode to get a discounted book. Plus the photo helped them find their car more easily at the end, leaving them plenty of time to read when they got home.