Take 2-9 business days to have your ads reviewed before they run in content network. If your CPM is to low or you do not have enough sites also you will not receive too much clicks - but you will need to sit and wait for the revision first.
I guess that explains why my ad is not up yet. I opened a new CPM campaign about a week ago and still not up yet...
You should write to Google people and ask for the exact reason for the delay. It should not be over two or Max three days. You are their customers and you have all the rights to ask why your ads are not running. Advertising is test of patience and courage. One day you see your money going the drain and your heart go in your mouth. It seems nothing works one day and then one fine day....Boom..... But keep faith and keep testing. Believe me when it rains, it pours Arvind Kumar
Oh, I have just set up a new CPM campaign and had noticed my sites traffic doing a little better straight after I had set it up, but now I guess that it must have been something else that made my traffic improve as I have been checking the stats every 30 minutes or so and I have had no impressions. But anyway, now I know that you have to wait until the ad gets approved first.