You have to read everything.
A FREE Membership gives you read access to forums, the ability to watch threads, and private messaging privileges, along with access to a limited library of members-only content if you confirm your email subscription to our Free Member List when you sign up.
A BASIC Membership gives you FULL access to forums, along with additional members-only content (above and beyond what you get with a Free Membership) if you confirm your email subscription to our Basic Member List when you sign up.
A PREMIUM Membership gives you FULL access to forums and FULL access to ALL members-only content, along with some exclusive sneak peeks into some of the programs available only to our Unlimited Members if you confirm your email subscription to our Premium Member List when you sign up.
An UNLIMITED Membership gives all the benefits of a Premium Membership, plus Insider Access into what’s happening behind the scenes at Backpacking Light, including strategic business updates, early access to selected content prior to publication, and the opportunity to participate in free or reduced-price beta participation in selected programs prior to their public release.
But I agree that “more content” should be better explained. I would not spring for the Unlimited membership.