Grubhub is an online and mobile food ordering platform that connects diners with local restaurants. It aims to help restaurants get more customers and online presence, while allowing diners to conveniently order food from different restaurants without leaving home. Grubhub makes money by charging restaurants commission fees for each order placed through its platform. It has expanded through acquisitions and the introduction of delivery services to over 50 cities. Key aspects of its success include improving the user experience through technology, marketing efforts, and integrating with partners like Yelp.