From Longman Business Dictionary
subscribersub·scrib·er /səbˈskraɪbə-ər/ noun [countableC]1someone who pays money regularly in order to have a newspaper or magazine sent to them, or to receive telephone, television or Internet serviceCountry Music Television currently has 15 million subscribers.
subscriber toWe are longtime subscribers to your paper.
2FINANCE someone who asks or agrees to buy shares in a company that is offering shares to the publicsubscriber forFinancial forecasts should be disclosed to intending subscribers for shares in the company.
3FINANCE someone who agrees to become one of the first members of a LIMITED COMPANY by signing the company’s MEMORANDUM OF ASSOCIATIONsubscriber toSubscribers to the memorandum must take at least one share each.
4a person, organization, or country that signs a documentsubscriber toBritain is not a subscriber to the convention.