Today we’re announcing a new metric in Bid Simulator, “Estimated Top Impressions,” which shows you how many times your ad appeared above the search results in the past seven days and how this metric could have changed had you used different keyword level maximum CPC bids.
Access the Bid Simulator by clicking the icon next to your maximum CPC bid.
Whether you carefully manage a handful of valuable keywords or simply want users to see your ad as often as possible, Estimated Top Impressions can be a useful metric. Ads that appear above the search results are more visible to users and tend to receive more clicks than ads that appear along the right side of the search results page.
Let's look at an example of how to use the Estimated Top Impressions column:
In this table, the current maximum CPC bid of $1.07 captures most of the impressions that a higher bid of $1.93 could have captured (7,520 vs. 7,930). However, when we look at the ‘Estimated Top Impressions’ column, we see that the current bid of $1.07 only captures a fraction of the top impressions (4,780 vs. 6,380). Increasing the bid to $1.93 would have placed the ad at the top of the search results page for many more queries, resulting in more users seeing the ad and clicking through to the site (591 vs 662).
If one of your goals is to appear in the top position and you’ve been focusing on the ‘average position’ of your ad to gauge how prominently it’s displayed to users, Estimated Top Impressions may be a better metric for you to focus on. While average position indicates where your ad is appearing in relation to other ads on the page, it doesn’t indicate whether your ad is appearing above the search results or on the right side of the page.
Note that past performance does not guarantee future results, and simulations will only be provided if there is enough traffic on a given keyword to conduct a meaningful analysis. Additionally, top of page impressions are counted only for impressions on Google, since other sites within the Search Network may display ads differently. Estimated Top Impressions data is currently only available in the Bid Simulator, and we’re working to incorporate this metric into more AdWords reports.
For an in-depth look at bidding, check out this tutorial from Hal Varian, the Google Chief Economist: Bidding Strategy Overview. 
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