As a website owner i would like to intergrate google adsense into the mailbox and login page(webmail)

this could be a feature that users could turn off and on as needed. 
would be a big selling point for people looking to use your service as no other service provides it
doesnt have to be google adsense but whatever is easier. i'm not sure if this is a relevant request or not. so i apologize if it sounds "stupid".  
thank you for your time