Displaying ads in a cloud product

I am aware of displaying ads in a static website like if I have a blog, I can simply register with google adsense and start displaying ads in my blog

Can I do the same for a cloud product?

My customers will be having different urls:

Assume my product name is "product_name"

Each customer will be having an instance of my product:

(eg) customer1.product_name.com customer2.product_name.com

How can I display ads in my web-app?