clarifying statistics

README.rst

@@ -11,7 +11,7 @@ can be considered a drop in replacement for libmemcached and
 
 libmc is developed and maintained by Douban Inc. Currently, it is
 working in a production environment, powering all web traffic on
-`douban.com <https://www.semrush.com/website/douban.com/overview/>`__.
+`douban.com <https://www.semrush.com/website/douban.com/overview/>`__. [#]_
 
 Build and Installation
 ----------------------
@@ -231,6 +231,12 @@ Documentation
 
 https://github.com/douban/libmc/wiki
 
+Footnotes
+-------
+
+.. [#] not an endorsement of the accuracy, just a publicly available reference
+ point
+
 LICENSE
 -------