Explain the importance of the Impression share metric.
Impression share metrics are the rate of an impression of the total eligible impressions for a particular ad. These can be calculated using several major factors such as targeting settings, approval statuses, quality, etc. This data calculated can be accessed for campaigns, ad groups, product groups and for given keywords. Impression share metric is one of the most important ways to elaborate on whether the ads will contain a reach of a greater number of people if the budget or bid is increased. It is used to find out whether the ad is viable or not.