When you’re setting up a new campaign, or changing bidding strategy, you go to the campaign settings, navigate to the bidding section and make your choice there. If you’re choosing a smart bidding strategy such as Maximise Conversions or Conversion Value, I strongly recommend to set it up as a portfolio bidding strategy instead, even if it’s going to be used in a single campaign.
By setting the smart bidding at portfolio level, you get the ability to set a maximum and minimum bid to your smart bidding strategy. In order for this option to be available though, not only should this be a portfolio bid but there should also be a target ROAS or CPA.
The first step is to set up a Maximise conversion or Conversion value at portfolio level.
Next, make sure to add a target ROAS or CPA.
Then scroll all the way down to Settings and click the down arrow to expand it:
You will then see this:
Click on Advanced Options to reveal the max and min bids:
If you’re running a single campaign or even multiple campaigns each with their own smart bidding strategy and you want to set a max or min bid, then the only way to do so will be to set all those bidding strategy at portfolio level to unlock this feature.
Even if you don’t want to set a max or min bid right now, you may want to do so at a later date, so it’s always a good idea to create the bidding strategy in a portfolio just in case. There is zero advantage to setting it up at campaign level. You can even set it up as a portfolio from within the campaign!