Just ask the user on first execution if small ads that don't use a lot of bandwidth and that don't track the user should be allowed and leave that as an option

Just ask the user on first execution if small ads that don't use a lot of bandwidth and that don't track the user should be allowed and leave that as an option in settings. The app could also provide a link to an example site for the user to see what the ad would look like. With iOS 9, it's also easier for the user to get back to the application after viewing the example site/page. I do commend Deck ads for having no cookies, no JavaScript, no counting clicks, etc. It's not a model for the entire web since many marketers want insights and statistics on users, but it definitely works quite well and is used on several popular sites.