I've just added an AdSense banner into my site, and it is empty.. how long does it take google to populate it with ads? thank's jony
If it is a newly created ad than not more than 10 minutes. If the ad was created before than it should show instantly.
If you have good quality content that is already indexed in google then you shouldn't have to wait more than an hour. For newer sites that perhaps aren't indexed yet it could be quite a while longer (say 24-48 hours). Its always best to have rich content for your sites prior to adding any google-related ad.