IUM SOCIUS, Inc. (이음소시어스) | 74 followers on LinkedIn. IUM SOCIUS, a startup based in Korea, is a leader and pioneer in Social Dating services across the globe. With proven business model and one-of-a-kind matchmaking process, IUM SOCIUS has been showing incredible growth in the last couple years. With more than a million users in South Korea alone, IUM has become more than just a brand, but a lifestyle.