Settings -> Interface -> "Notify me about additions or changes..." to disable it, by the way.

Thanks, but it's still pretty scummy how hidden that is. This could have just been a checkbox on the pop up.

Yeah absolutely, I don't disagree.

Steam is also a launcher and when I use it as a launcher I don't want to see ads for the store and burying a setting to turn if off in the settings is not sufficient. At the very least let me turn it off on the pop up.