 What does removing price barriers mean for readers?
Shifting from ink on paper to digital text suddenly allows us to make perfect copies of our work. Shifting from isolated computers to a globe-spanning network of connected computers suddenly allows us to share perfect copies of our work with a worldwide audience at essentially no cost. Digital technologies have created more than one revolution. Imagine a tribe of authors who write serious and useful work, and who follow a centuries-old custom of giving it away without charge. It’s enough to know that their employers pay them salaries, freeing them to give away their work, that they write for impact rather than money, and that they score career points when they make the kind of impact they hoped to make. Suppose that selling their work would actually harm their interests by shrinking their audience, reducing their impact, and distorting their professional goals by steering them toward popular topics and away from the specialized questions on which they are experts. If authors like that exist, at least they should take advantage of the access revolution. The dream of global free access can be a reality for them, even if most other authors hope to earn royalties and feel obliged to sit out this particular revolution. A price tag is a significant access barrier. Most works with price tags are individually affordable. The resulting access gaps harm authors by limiting their audience and impact, harm readers by limiting what they can retrieve and read, and thereby harm research from both directions. OA removes price barriers. Copyright can also be a significant access barrier. As a result, users may be hampered in their research by barriers erected to serve intermediaries rather than authors. Removing price barriers means that readers are not limited by their own ability to pay, or by the budgets of the institutions where they may have library privileges. Removing permission barriers means that scholars are free to use or reuse literature for scholarly purposes. These purposes include reading and searching, but also redistributing, translating, text mining, migrating to new media, long-term archiving, and innumerable new forms of research, analysis, and processing we haven’t yet imagined. OA makes work more useful in both ways, by making it available to more people who can put it to use, and by freeing those people to use and reuse it. While every kind of OA removes price barriers, there are many different permission barriers we could remove if we wanted to. If we remove price barriers alone, we provide gratis OA , and if we remove at least some permission barriers as well, we provide libre OA .
 Readers are not limited by their own ability to pay.
 Readers are not limited by the budgets of libraries.  Readers can translate and redistribute work.  Readers can reuse literature for scholarly purposes.  Readers are not limited by their own ability to pay.