Developer ads in frontend plugin

Hi

Here’s my question.

Is it okay to add default ads in the frontend part of a plugin. I have searched the codex for such rules but found none.
Basically I am an amateur developer and at the moment I starting development of a plugin.
This plugin renders a frontend interface that has ad serving capability. It enables users to add ads in the frontend interface. Now before users add the ad code to the plugin so it renders in the front end I would like to add mine as default and also to serve as an example for the code.
If a user chooses to Not add there code then they can either remove mine or they can add there own code. Its up to them. So in no way is it forced ads.

Is this okay?