1) Bidding High for Keywords with Low Purchase Intent
Avoid bidding on single word keywords like the plague. This would include keywords like "Gym", "Kitchen", "Pet". The reason being that people who are searching these vague search terms are at the very beginning of the purchasing process. They don't know exactly what they want so they are clicking around to find products or subcategories that they might be interested in. It's a game you don't want to be involved in!
Take the alternative to this, "Gym heavy bag hook". If someone is searching this exact of a term, they are much more clear with their buying intent. They know specifically what they want, which is why you will get a far better return bidding on 3-5 word keywords like these.
2) Disorganized Structure
If your ad groups have over 100 keywords in them then you are making the cardinal error of a disorganized PPC structure. Why is this bad? There are several reasons.
- Can't pause (optimize) products based on keywords working well or not
- Can't get a high level overview of what concepts are working or need attention
- Does not provide amazon with an effective CTR in order to boost impressions of Ad Groups
- If you used this method while working at an Ad Agency, you would probably get fired.
Instead of throwing all of your keywords into one ad group, organized them into multiple ad groups each with a focused topic.
3) Keyword Jumbles
Similar to Rule #2, if the keywords in your Ad Groups are only somewhat related to each other, this will prove to be problematic. For example if your ad group has competitor names, similar products, your main keyword, variations of your main keyword, more competitor names... etc. - Then you know you are committing this sin.
Often times these types of keyword jumbles will come from Amazon's Suggested Keywords, or a tool that scrapes from your competitors, or might be a list of similar terms based on your main keyword. All of these keywords will be provided to you in a disorganized way, and it's up to you to set up your campaigns in a way where you can sort the mess.
4) Bidding too High for Auto Campaigns
Rule #4 is the easiest to implement, and is generally overlooked. High bids for Auto Campaigns almost always lead to high aCos! Across all of my clients, I've found that bids in the .50c range outperform $1.50 all day long.
Amazon shows your listing to a shotgun spray of search terms, some of which you might not want to show for. These can be negated using "negative keywords", but in general a high bid for Auto Campaigns will net you poor results. Go for that .40-.55c range and you might be amazed at what happens!