The canonical discussion of access-control mechanisms such as paywalls and DRM is that people ought to pay for stuff. That's not a wholly ridiculous idea; I've repeatedly asserted that creative people ought to get paid for what they do.

The problem? How do you know who has and who has not paid, particularly when you present your content in multiple ways on multiple platforms? This was brought to my attention by a column written by usability expert Jakob Neilsen.

Neilsen critiques the Wall Street Journal's iPhone app for its confusing user interface. In particular, the app appears to be asking people to pay twice for WSJ content. This causes the app to get horrible reviews. Neilsen points out that a fairly simple redesign could fix this particular app's problems, but I see this as symptomatic of a bigger issue.

By paywalling its content, the WSJ has taken on the burden of keeping track of who has and who has not paid. And, sensibly enough, the human being who pays for the content feels like she ought to be able to access the content she paid for, whether it's on her desktop or her mobile device. In fact, what is happening is that the WSJ, through poorly thought-out design, is transferring this burden to the end users who are then pissed off by being asked to pay twice for the same content.

Entities (people, corporations) who lock up their content behind automated mechanisms need to start paying attention to this, or they're going to be dealing with a lot more pissed-off customers. Paywalls already cut your subscriber base significantly (90% or more from figures I've seen). How much does it cost you to alienate that last 10%?