How the economics resolve

Break-even ACOS, Target ACOS and Max bid can each be set in four places. When a decision needs one of them, the App takes the most specific value that exists.

Resolution runs top to bottom and stops at the first level that has a value. A level you have left blank is skipped rather than counted as zero.

Reading it in the table

Each value in the ASIN table carries a badge naming the level it resolved from. A line badge means nothing more specific was set, so the Product Line’s default is in force.

That is how you tell an inherited 50% from a deliberate 50%. They look identical in the column and behave differently the next time you edit the line.

Inherit or override?

Leave it inherited when the ASIN behaves like its line. An inherited value keeps following the line, so when your costs move you change one number instead of forty.

Override when the ASIN genuinely differs — a size whose margin is not like its siblings, a product you are defending, a variant that attracts a different shopper. An override stops listening to the line permanently, which is the point, and also the cost.

The common mistake is overriding to make one bad week look better. That value is still there six months later, quietly ignoring every update you have made since.

Where these values are used

• Break-even ACOS bounds what a losing target actually costs you.
• Target ACOS is what a Bidding rule aims at — gradually, if glide is switched on. See Creating a Product Line.
• Max bid derives the bid ceilings that rule-set and proposal bids must stay inside.

The bottom level is a system default, not one of yours — so a badge reading default on a row means the opposite of what it looks like: nothing you configured supplied a value, and a built-in fallback did.

Break-even ACOS and Target ACOS always resolve to something for that reason. Max bid does not — it has no system fallback, so an ASIN that reaches level 4 has no bid ceiling to derive, and the limits that depend on it cannot be applied. Setting an account default Product Line, and giving it a Max bid, is what stops that happening for unassigned ASINs.