Keyword Difficulty (KD)
Keyword Difficulty (KD) is a metric that, according to my observations, causes a lot of confusion in our industry. So let’s explain it in detail.
We calculate the AdCostly KD score by taking a weighted average of the rank of the advertiser to use this Interest, audience size rank, CPC rank, and CPM rank on a logarithmic scale from 0 to 100.
KD takes into account only 4 variables ( Advertisers numbers, Audience size, CPM, CCP ).
We know that the effectiveness of advertising is not only determined by these four variables, it also involves variables such as the quality of your creatives, your copywriting, etc.
KD effectively tells you the average height of the other players in the game. The higher the number, the more height you’ll likely need to participate in bidding ranking.
Bottom line: KD is useful for estimating how difficult it may be to participate in bidding ranking, but keep in mind that it doesn’t tell the full story because it’s based on only 4 ranking factors.
Furthermore, it makes no sense to compare AdCostlys’ KD score to similar metrics in other tools because they probably don’t calculate their scores in the same way.”
In short, you can choose an Interest word with a relatively low KD, and at the same time, it has a larger audience, to place your advertisement, which can help you better predict the effect of the advertisement and save some advertising costs.