In order to know which metrics matter for your online paid ad campaigns, you first have to know your goals. Without S.M.A.R.T. goals (Specific, Measurable, Attainable, Relevant and Timely Goals), you could end up tracking the wrong metrics, making the wrong decisions, and wasting/losing money.
While advertising’s priorities are increasingly focused on long-term customer relationships, the value of impressions and web traffic indicates that advertisers also remain dedicated to acquiring new business.

Take a glance at the most important metrics that advertisers mentioned that it is important in optimizing their Ads:

• 27% of surveyed marketers reported that the lifetime value of a customer is an important metric to optimize their Ads.
• 19% indicated that impressions or web traffic from digital advertising is an important metric for optimizing their Ads.
• 18% said that brand recognition and lift is an important metric considered in optimizing their Ads.

                   A Graph Shows The Important Metrics To Optimize Ads by Advertisers.