title: Admob advance native ads fetch in background?
body: <p>Loading admob ads makes the app startup really laggy, it looks like admob uses WKWebview which runs on the UI thread.</p>
  <p>Is it ok if i fetch (<strong>fetch data without displaying them</strong>) the ads in the background and keep them in memory so that when the app starts up or comes to foreground it doesn't lag? Are there any guidelines against this?</p>
  <p>My users generally visit the app every 2-3 hours, so there is a good chance the app is not killed and the ads remain in memory for future use</p>