Chart 1 below shows the normal price of a tablet computer in different stores (in US dollars), and the % discount offered by these stores when the products are sold on promotion. Chart 2 shows the % increase in volume sales when the discount promotions are happening, and Chart 3 shows funds (in 000 US dollars) spent on TV advertising during these promotions. Write a report summarising the information. Select and describe the main features, and make comparisons where relevant.