org-agenda-sticky

org-agenda-sticky is a variable defined in `org-agenda.el'.
Its value is

nil

Documentation:
Non-nil means agenda q key will bury agenda buffers.
Agenda commands will then show existing buffer instead of generating new ones.
When nil, `q' will kill the single agenda buffer.

You can customize this variable.

This variable was introduced, or its default value was changed, in version 24.3 of Emacs.