You will start to get notices when you're nearing your
impressions limit. You will get notices every few days as
well. You account will remain displaying ads as long as you
don't exceed 25% overage.
Some key things to remember.
1) Our system will only suspend your account after notifying
you over several days. By time accounts are suspended, they
would have received at least 3 notices spread two days apart
since our system will not check your account again for 2 days
after a notice is sent.
2) You must go over your limit by 25% before it will suspend