All ads need to be validated and approved by our Compliance team before the campaign can receive traffic. This process is generally fast and you will be notified via email upon approval. Usually we moderate ads a couple of times per day. Depending on the queue it might take up to 4 hours (during working hours) before your ad set live.
When your ads have been approved your campaign will start within a few minutes.
It is also important to remember that you need to have available budget in your account in order for your campaign to start.