One of the advanced and accurate metrics inside Keyword Spy is the ROI.
ROI (Return on Investment) is an extrapolated profitability metric computed by the KeywordSpy to gauge how effective an ad is based on two factors: the length of time the ad is running and the frequency of time the ad was seen in search engines.
The maximum ROI of an ad can be equal to the number of days it has been displayed online. It can be adjusted through the member's "Account" page for you to set what ROI you would consider to be profitable in relation to your campaigns.
In turn, ROI numbers higher than the value you will set will reflect as a green bar on your search results, and gray for lesser values, making it easier for you to evaluate between profitable and non profitable ads and keywords.