have buttons all around the app where you want ads. you need cloud variables for the following:
button visibility
button background picture
button when clicked, open link value
and if you want to get all complex, you could have values for height and width.
one of these. for every add on the app. could be 20, then with 3 different options, you need 60 cloud variables. unless all the ads look and will show the same, then only 3