Low ACoS: If ACoS < Target ACoS - 2,5% after 150 clicks
--> increase ad group bid by 20%
High ACoS : If ACoS > Target ACoS + 2,5% after 150 clicks
--> decrease ad group bid by 20%
Keyword Rules Suggestion for 0 Sales
Bid Rules cannot provide a solution for targets or ad groups with 0 sales, as there can be no ACoS without any revenue.
Therefore it is also recommended to set up Keyword Rules, in order to, for example, pause such a keyword or set it to negative.
Defensive vs Aggressive Rule-Sets
Depending on your strategy, you may want to be less or more aggressive - for instance to help push the keyword rankings of new products.
A more defensive strategy could mean decreasing bids by a higher % (eg. 30), while a more offensive strategy could mean the same for increasing bids.
It is therefore a good idea to create additional rule-sets for those kind of scenarios.
This article (click here) explains how to determine the Target ACOS.
This article (click here) explains what 1X/1,5X means, ie. how many clicks you should wait.