Membership Levels can be set to Access the desired Protected content.
Content Protection basically works as an On/Off switch.
Pages, Posts, Categories, etc. can be set as Protected or Unprotected.
Membership Levels can be set to have Access to the desired Protected Pages, Posts, Categories, etc.
To summarize, you select which Membership Levels can Access the Protected Content.
Protection and Access can be set in the Content section of WishList Member.
Setting Protection Screenshot: http://screencast.com/t/NEZhlmkkrRGN
Setting Access Screenshot: http://screencast.com/t/LWgCM9MufK
Note that Protection and Access can also be set for a Page or Post in the edit section of the Page or Post.
The Protection and Access settings for an individual Page or Post can be viewed or edited in the edit section.