To view the estimated forecast for a keyword bid and the estimated bid range for prime placement of a keyword:
1) Click the Campaigns tab and then the Keywords subtab. The Keywords page opens. (Alternatively, if you want to work with keywords from one specific ad group, you could click the Campaigns tab and then the Ad Groups subtab. When the Ad Groups page opens, identify the ad group and click its link. When the Ad Group Details page opens, click the Keywords tab in the bottom of the page.)
2) Identify a keyword in the table and click its Bid link. The Set a Bid dialog box opens.
3) In the Set a Bid Dialog box, youíll notice the following:
In the Estimated Monthly Forecast graph, the red line represents your current bid for the keyword and indicates an estimate for clicks and other statistics that you may receive for this bid. You can move the red line with the slide control to see how different bids may affect clicks.
The section with the label Recent Bid Range for Top Positions shows the bid range based on the most recent data available that would place your ad in the top available positions for the keyword. Bid and ad quality are used to determine an adís position in search results.
Hope this helps.