As we once explained in our How-To on Digital Rights Management, DRM should be a strategy that helps your maximize revenues — not a burdensome technology that locks out prospective subscribers.

HBO seems to understand the nuances of this idea more than most paid content providers. CEO Richard Plepler recently admitted that the company is aware that cable subscribers are sharing their passwords so that family and friends can view HBO content on HBO Go.

“”It’s not that we are unmindful of it, but it has no real effect on the business,” Plepler said, according to GigaOm.

Plepler’s laissez-faire attitude illustrates a solid understanding of digital content economics. By sharing passwords, HBO subscribers are exposing new viewers to HBO content. Since passwords are most often shared between family members, often parents are sharing their passwords with college-aged children, a percentage of which will likely subscribe after their college years and once they’re “hooked” on the content.

Of course, HBO is not playing fast and loose with its content either — there are some controls. Specifically, HBO only lets three devices stream content at once, and periodically, users have to re-activate their devices.

However, the other reason for HBO’s laid-back approach is that it really can’t punish the people infringing on their content, only current subscribers who share their password. By going after current subscribers, HBO would threaten its bottom line more than if they view password-sharing as the best form or word-of-mouth marketing.

Need more evidence that you should take a laid-back approach to dual logins and password sharing? Consider this — pirated downloads of ABC shows shot up 30% after ABC restricted next-day viewing online.