It is very easy to use:
Go to “widgets” and only drag and drop the ‘visual editor’ to ‘call to action’ or the place you want your advertise to appear.
Than chose the ‘html’ register and put in your code for the advertise.
This way you can add several advertises or simple text etc.
With the plugin “Dynamic widgets” you can choose on wich sites or articles you want it to appear.
Andre did a tutorial how to use this plugin in his tutorial.