In a straight rebuy, the suppliers make an effort to maintain product and service quality and automate reordering systems to save time. For a supplier to break into this system and capture more market, he has to offer something new or exploit dissatisfaction with a current supplier. He can get a small order and then enlarge their purchase share over time.
Example: an example for straight rebuy would be the purchase of office supplies or bulk chemicals. The order quantity and specifications are routine, and the purchase is made from the same competent supplier at regular intervals, without any decision making process.