diff --git a/README.md b/README.md
index 3f0306e..bd1803c 100644
--- a/README.md
+++ b/README.md
@@ -1,7 +1,7 @@
 # itconfig
 [![Build Status](https://travis-ci.org/icetemple/itconfig-rs.svg?branch=master)](https://travis-ci.org/icetemple/itconfig-rs)
 [![Documentation](https://docs.rs/itconfig/badge.svg)](https://docs.rs/itconfig)
-[![Crates.io](https://img.shields.io/badge/crates.io-v0.7.1-orange.svg?longCache=true)](https://crates.io/crates/itconfig) 
+[![Crates.io](https://img.shields.io/badge/crates.io-v0.8.0-orange.svg?longCache=true)](https://crates.io/crates/itconfig) 
 [![Join the chat at https://gitter.im/icetemple/itconfig-rs](https://badges.gitter.im/icetemple/itconfig-rs.svg)](https://gitter.im/icetemple/itconfig-rs?utm_source=badge&utm_medium=badge&utm_campaign=pr-badge&utm_content=badge)
 
 Easy build a configs from environment variables and use it in globally.
diff --git a/itconfig/src/lib.rs b/itconfig/src/lib.rs
index c17ff14..0bb0216 100644
--- a/itconfig/src/lib.rs
+++ b/itconfig/src/lib.rs
@@ -3,6 +3,15 @@
 //! Simple configuration with macro for rust application.
 //!
 //!
+//! ## Motivation
+//!
+//! I began to use rust with web programming experience where environment variables are widely used
+//! and often there are more then 50 of them. First I looked at already created libraries.
+//! But there it's necessary to initialise structure that needs to be moved to each function
+//! where you need variable. It uses little bit memory, but configuration lifetime is as long
+//! as application lifetime. Because of it I decided to create my own library.
+//!
+//!
 //! ## Example usage
 //!
 //! ```rust