Juan is very keen to run a major marketing campaign to support the Smart brand name. Until now, Smart Sports has used trade newspapers and the internet to advertise its kits and racquets, but Juan is now proposing to run a radio campaign. He has already spent £50,000 on production costs and is committed to radio slots in two regions at a cost of £10,000. He is considering whether to pay for three further regional slots. It has been forecast that the campaign will increase racquet sales, making a total contribution of £100,000. By running a radio campaign, the business will not be able to run a series of newspaper advertisements from which it had hoped to generate an additional £25,000 contribution. Nina helps Juan to assess whether it is financially beneficial to pay for the further three regional slots at £5,000 each. What will Nina advise?