Andromo allows you to define one or more devices as 'test devices' so that you will only be shown test ads on your device. You're encouraged to do this to prevent false impressions/clicks. You can get your device ID by installing Andromo's Device ID Utility App on your device(s), copying each ID and entering them in the "AdMob Test Device IDs" field.
My app after building showed ads only the first day, after then till now it no longer show ads. I had to follow a comment here, created another admob account thinking the issue could be from admob,even with the new account it isn't still showing ads. Please how do i resolve this?