I have recently added Adsense to Crenk.
I wondered how long it takes before the ad code starts to show correctly on your site once it has been added.
Answer = random.
If your using the same Google account or the same IP address as you did when you inserted the code then Google won’t show you an ads and you will see a big white blank space.
However, if you get in touch with a friend and get them to test the site for you then they should be able to generally see the ads. It normally takes a few hours after the ad has been inserted, but sometimes it can be faster.