Mobile media company Blyk has announced that it now has four million opt-in subscribers around the world, up from one million at the end of 2010. Blyk’s service provides updates, promotions, trivia and polls that members have indicated are relevant to them. The company attributes its increase in subscriber numbers to the service’s ability to reduce churn, improve operator brand perception and expand customer base. Blyk’s operator partners include Everything Everywhere in the UK and India’s Aircel.