In a product innovation approach, the company pursues product innovation , then tries to develop a market for the product. Product innovation drives the process and marketing research is conducted primarily to ensure that profitable market segment(s) exist for the innovation. The rationale is that customers may not know what options will be available to them in the future so we should not expect them to tell us what they will buy in the future. However, marketers can aggressively over-pursue product innovation and try to overcapitalize on a niche. When pursuing a product innovation approach, marketers must ensure that they have a varied and multi-tiered approach to product innovation. It is claimed that if Thomas Edison depended on marketing research he would have produced larger candles rather than inventing light bulbs. Many firms, such as research and development focused companies, successfully focus on product innovation. Many purists doubt whether this is really a form of marketing orientation at all, because of the ex post status of consumer research. Some even question whether it is marketing.