Understandably, you might be eager to see how well your carefully crafted campaign works out, but the truth of the matter is that it might take some time before you start seeing results. PPC campaigns rely on algorithms to ensure your ads are being displayed in the right places and to the right people. Waiting about 2-3 weeks will allow the algorithm the time it needs to adjust while providing you with enough data to start noticing trends and patterns of behavior in response to your ads.