From there, I work manually to keep the budgets fluid between campaigns – meaning that I will manually shift funds between campaigns. If one is outperforming another and can take on more budget, then I will make the necessary shift.
We make decisions on budget migration through manual tracking (which I prefer, though there are plenty of ways to do it) of spend pacing. I like to do this daily as it keeps us fresh, but you’ll know the right interval for your team.
Then, compare the campaigns against which campaigns are meeting or exceeding our objectives vs. those that are underproducing against the objectives.
When Are Shared Budgets Appropriate?
This is a bit subjective, but there are times when it can become appropriate.
One of the more common ones is when you’ve split your campaigns by devices (i.e., Campaign 1 is mobile-only, and Campaign 2 is desktop-only).
Here, presumably, the keywords, assets, and targeting are all the same, but it just so happens you have a justified reason to split the campaigns. So, having the campaigns share a budget is fine.
But you should closely monitor performance, as mobile often takes the lion’s share of traffic and may cause campaign cannibalization of desktop. (This was less of a problem back in the day when mobile cost per click (CPC) was significantly lower than desktop, but 55%-65% of the total traffic.)
This can also be applicable when multiple campaigns have the same assets and targeting but are splintered by match type at the campaign level – which, believe it or not, is still a common practice.
A shared budget works fine, and in theory, it would replicate the situation if you split the match types in a single campaign but at the ad group level.
The only caveat is that broad match will need to be watched like a hawk, as that often tends to be a driving force of search volume.
Another one is when using a portfolio bid strategy. When a group of campaigns share a single goal, and there is no disproportionate demand in volume, they can be put into a shared bid strategy.
This is a time when using a shared budget makes sense, as all elements are working together for a common goal (sort of like a Performance Max approach with the different ad units).
Image from author, October 2024
The Takeaway
First, a friendly reminder that shared budgets aren’t even applicable to all campaigns (i.e., campaigns in experiments or Performance Max don’t qualify to use them).
Next, if you are using shared budgets: Before you go and make changes to opt out of them after reading this inspirational article, you must first do some analysis.
In campaigns using a shared budget, look at things like:
Is one campaign considerably outperforming another one in terms of return?
Is one campaign consuming a disproportionate amount of the budget (and not the top performer of those who share the budget)?
Do you have the bandwidth to manage and maintain individual campaign budgets? Always calculate the cost of manpower when doing return analysis.
If they have a portfolio bid strategy, is the budget also shared?
If you do use shared budgets, make sure you account for the following (this is going to sound like a broken record, but deal with it):
Brand and non-brand have different volume, different efficiency, different cost. If they are separated at the campaign level, then they shouldn’t share a budget.
“Church and State Separation”: Display, Search, Shopping, and Video are different channels, are measured different ways, and serve different purposes. Therefore, sharing a single budget across channel types will lead to cannibalization.
Make sure the campaigns you share budget for, have the same objective: traffic, conversions, etc.
If you’ve done this, and decided it would benefit you to try an individual budget over a shared one, then absolutely proceed and test it out.
Just keep in mind that you may see an improvement in your target campaign but run the risk of an adverse impact on the other campaigns that shared the budget.
Happy search marketing!
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Featured Image: Vitaly_Vision/Shutterstock