What is the difference between a campaign and an adgroup?
When should you use a campaign instead of an adgroup?
The short answer is that there isn’t much of a difference. You only set an adgroup as a campaign if you don’t want it to inherit the same campaign settings and if you want more control over it. This is best explained by way of an example.
Let’s say you’re advertising shirts. You have multiple adgroups for cotton shirts, long-sleeves shirts, beach shirts, etc. They’re all happily getting along with each other within the same campaign.
Then you find that the adgroup for cotton shirts is spending a lot more than the rest and the performance is poor. You can adjust the TROI or TCPA target at adgroup level, so that’s not an issue. But you can’t adjust spend at the adgroup level, so you set up a new campaign for cotton shirts so you can control spend closely and allow the other adgroups to spend more, especially if they have a better ROI.
There are various other campaign settings not available at adgroup level such as location targeting, but these usually tend to be the same for all adgroups, unless the business is geographically-oriented.
In this example, we get two more advantages with having this new campaign: