There are five key factors that influence how the bidder will perform based on your MACS.
1. Goal/Objective of the Campaign:
Launch → Increase Sales → Higher MACS
Profit → Reduce Spend → Lower MACS
Think about where your products are in their life-cycle (how long has it been advertised) to help determine your 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. Pre-Ad Gross Margins of the products:
Margins help you understand how much you can spend on ads while remaining profitable.
Group products with similar margins together in campaigns for optimal performance.
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. Category Competition:
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 41%.
Setting MACS that is more than 10% lower than the current campaign ACoS may 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 Phase.
5. Campaign Structure:
MACS are set at the ad group or campaign level. MACS set for campaigns will apply to all ad groups, and you have the ability to use different bidding strategies based on the goals of different ad groups.
When to Make Changes to MACS
Next: Quick Tips for Setting & Adjusting MACS