This is not a listicle written for search engines. It is the list of things we genuinely find, in roughly the order of how often they show up when we open an account someone else was running.
1. Broad match with no negative list
Broad match gives Google permission to wander. With conversion data and a maintained negative list, useful. Without either, it is an expensive education. Read the search terms report — it is the most boring, highest-return job in account management.
2. Add-to-cart as a primary conversion
The account optimises for people putting things in carts. You get a lot of carts. That is not a business.
3. Target ROAS on a campaign with almost no conversions
Smart Bidding needs a steady flow of sales to learn. Below that it is guessing, and the fix is not a better target — it is more volume, or manual control until you have it.
4. Bidding on brand without knowing it
Often 40% or more of "performance" is people who typed your name. Split it out and the account tells a very different story.
5. One PMax campaign holding the whole catalogue
Your best-margin products subsidising dead weight, with no visibility into which is which.
6. Disapproved products nobody checked
A disapproved product earns nothing and generates no email. We regularly find double-digit percentages of a catalogue sitting disapproved for months over missing GTINs.
7. Location settings including "people interested in"
The default setting reaches people interested in your target location, not just people in it. For a store that only ships domestically, this quietly buys foreign traffic that can never convert.
8. Ad schedule and device data never looked at
Not always a lever, but when an account has months of data and mobile converts at a third of desktop at the same CPC, that is worth knowing.
9. Nobody reading the change history
The account keeps a timestamped log of every edit, and you own it. An account with no changes for three weeks is an account nobody is running. It is the single best check available on an agency and almost nobody uses it.
Tools > Change history. Two minutes. It will tell you more about your agency than any report they send you.