At the current time of this writing the most recent version of WordPress is version 4.6.1 and this is the version we will be using in these instructions. We will be using version 1.11 of the EmbedIt Pro plugin. Do not mind that the WordPress site says this plugin is potentially out of date -- it does in fact work with the latest version as you will see.
First go to the EmbedIt Pro plugin page on the WordPress site and download it.
Next you will want to log in to the WordPress admin and navigate to the Plugins menu.
Click on the Upload Plugin button and select the embedit-pro.1.11.zip file from your computer.
Click on Install Now button as shown above and then click on the Activate Plugin link once it has been installed successfully.
Now you should see there is a new HTML Snippets menu and you can click on Add New to create a new snippet as shown below.
This shortcode can now be inserted into any post or page as shown in the following screenshots:
The plugin also comes with an HTML Snippet widget, which is great for including ads in your sidebar as shown in the following screenshot:
As you have learned the EmbedIt Pro plugin allows a simple and seamless integration of AdvertServe tags into WordPress posts, pages and widgets. It is also perfectly fine in certain cases to insert ad tags directly into the PHP template files for your Wordpress theme. However, this should be reserved for cases where a shortcode cannot be used. In general you want to limit modifications to your theme templates as it complicates upgrading your theme to newer versions.