Queues for discount airfares just keep growing. More than half of Australian air travellers now choose low-cost carriers. But passenger complaints about budget airlines’ services have also been hitting new highs. Rapid growth may underpin poor customer service, says Australian School of Business marketing professor Murali Chandrashekaran. Part of the problem is that cut-price airlines are now catering to such a wide range of customers. And, despite the carriers’ increasing popularity, they can’t afford to sit back and relax.