DC Universe is acting on its promise to deliver DC's full comic book library -- more or less. As of now, subscribers to the service have access to 21,000 issues stretching over 80 years, so long as a given issue was released at least one year before a given date. You can't use this to catch up on the latest story lines, but this should help you find a beloved issue of Batman or Wonder Woman without having to buy it or subscribe to a separate comics-only offering.