Update README.md

README.md

@@ -23,6 +23,13 @@ Send data to Google Analytics from the server using PHP. This library fully impl
 * Content Experiments
 * Content Grouping
 
+## Sponsor
+
+If you use this library, please consider to [:heart: Sponsor](https://github.com/sponsors/jorgeborges). Reaching the goal you can see in my sponsor page will allow me to focus on:
+- Upgrading the library to support PHP version >=7.2
+- Keep dependencies up to date
+- Fix any critical bugs
+
 ## Installation
 
 Use Composer to install this package.