The stuff, as they say, sold itself. If these profits are reinvested in marketing or additional product development, they are removed from the profit sheet — which means a highly successful but swiftly growing company can show no profits on paper, or even a loss if investment capital is still flowing. Advertising for this can be difficult; seek out those who might actually be able to use your services and advertise directly to them. Thanks to technology, there are more opportunities than ever to buy and resell products for extra money.