diff --git a/README.md b/README.md
index 5d0d0bf..faff90f 100644
--- a/README.md
+++ b/README.md
@@ -2,3 +2,16 @@ vim-dnsserial
 =============
 
 Another DNS-zone serial number updater.
+
+
+Why?
+----
+
+I know this not the first vim plugin available to update a DNS-zone serial number. Here is a few reasons why I chose not to use the canonical one:
+
+* there is no license and therefore it is not free;
+* it is unmaintained;
+* it is bugged;
+* it lacks functionalities.
+
+It chose not to fork the original plugin but to write a new one from scratch mainly for legal purposes, but also because I did not found the code as simple as I expected.