If an Ebook Central site is enabled with anonymous access for certain IP addresses, patrons coming from those IPs can browse without signing in, but by default all patrons will be prompted to sign in to their personal Ebook Central account if they attempt to:
However, librarians can choose to enable an Ebook Central site with a "Continue as Guest" option.  

If "Continue as Guest" is enabled, 
Patrons can do the following activities without signing in to a personal Ebook Central account:
But patrons will still be required to sign in to their personal Ebook Central account to do the following:

There are two levels of "Continue as Guest":
1. Offer patrons the "Continue As Guest" option when they would otherwise be required to sign in:
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2. Automatically sign patrons in as a Guest when they would otherwise be prompted:

To request "Continue as Guest" for an Ebook Central site, librarians can contact the Technical Support Team by submitting a case through this form.  Typically we do not recommend this option unless the site only has subscriptions and/or unlimited-user perpetual titles, and is using 'Patron Login' authentication.

Important points: