Machala, the capital of El Oro Province, is an important city for Ecuador’s banana production. In fact, because of the area's mass banana production and exportation, it is sometimes referred to as the "banana capital of the world." There is even a festival in late September that includes the Banana Queen of Machala contest.
Although Machala is an important hub for business in Ecuador, and thus home of a decent amount of conventions and meetings, it is not often frequented by foreigners. Usually it serves as just a stopover for travelers on their way to Peru. Those who do happen to end up in Machala will not be disappointed. It may not have a ton of things to do, but there is a beach, as well as an ample supply of hotels and restaurants. There are definitely worse places you could end up for a stopover.