There are four key factors that influence how the bidder will perform based on your MACS. Let's look at how each factor influences performance.
1. The Goal/Objective of the Campaign:
Launch → Increase Sales → Higher MACS
Profit → Reduce Spend → Lower MACS
Think about where your products are in its life-cycle (how long has it been advertised) to help you determine accurate goals. Products with at least 180 days of sales data are favored more by Amazon’s algorithm and could require a less aggressive advertising approach to generate sales.
2. The Pre-Ad Gross Margins of the products:
Margins give you an idea of how much room you have to spend on advertising to turn a profit.
Grouping products of similar margins together will prevent you from over or underspending on your campaigns.
If you have products with a pre-ad gross margin range over 10% within a campaign, consider grouping these together in their own campaign. Grouping products by parent ASIN, if you have lots of variations, will yield the best results.
3. The competitiveness of your Category:
Higher MACS are needed for more competitive or saturated categories. Increased competition results in higher CPC, to remain relevant, you need to have a higher willingness to spend.
Competitive Categories: cell phone accessories, pet supplies, supplements, grocery (keto, tea), health & beauty, kitchen items, etc
4. The Current ACoS of the Campaign: “10% Rule”
As a rule of thumb, you should always aim to set a MACS within 10% of the current ACoS or higher. If your campaign is running at 45%, you would not want to set MACS below 35%.
Setting MACS that is more than 10% lower than the current campaign ACoS will result in a decline in sales.
If a campaign has no ACoS, we recommend setting a MACS between 40%-99%, depending on your margins and category. This will speed up the ‘Discovery’ process.
5. Campaign Structure:
MACS are set at the campaign level, if you have ad groups within your campaign that hold products of with different goals, gross margins or of a different category, you will want to restructure your campaigns.
When to Make Changes to MACS
Next: Quick Tips for Setting & Adjusting MACS