Inferior restaurants, iffy payment processing (sometimes PayPal and credit card payments work flawlessly, other times they don't work at all), way off delivery times (food arrives way sooner or way later than estimated delivery.) Now I know most people probably wont complain about an earlier than expected delivery, but sometimes this too can be annoying. Imagine being told that you have around 35-45 minutes before your order arrives, so you decide to hop in the shower, maybe shave and get dressed, only to end up with an angry delivery person on your doorstep threatening to take the food back to the restaurant when they arrived away ahead of the expected delivery time. The other extreme is waiting for what feels like hours for food from a restaurant that you could have walked to and back from multiple times. A restaurant that is never very busy and is presently in a slow period when you place your order. These are just a few areas where Grubhub needs to improve.