Investing.com - Fast food is slower.That's because more and more fast food chains are taking online orders and delivering the food to their customers.Yum! Brands (NYSE:YUM) is the latest industry player to join the trend, teaming with GrubHub to provide online order and delivery service for its Taco Bell and KFC restaurants.Customers don't seem to mind the wait or the extra cost, and even tend to order more food, lifting profits. The food delivery industry generated $43 billion in 2017 and is expected to grow to $76 billion by 2020.Chains from McDonald's (NYSE:MCD) to Wendy's to Dunkin Brands all provide delivery now.Companies like GrubHub, DoorDash, Caviar and UberEats are cashing in on new opportunities to take and deliver orders.The initiative appears to be a game changer. One Wall Street firm recently upgraded McDonald's stock, saying its digital and delivery efforts will help boost sales