Introduction

When applying a boost to a Facebook post in the Message Booster, you might encounter the following error:
 

For example, the minimum budget would be 40 USD instead of the expected 5 USD:

What Causes The Issue?

This issue occurs when the Message Booster optimization strategy has not been selected for the Media Plan parameters in the Message Booster.
 

How To Fix The Issue

To fix this issue, you'll need to update the Default Bidding settings in the Media Plan parameters by following the steps below:

1. First, navigate to the relevant Media Plan and click Parameters.
2. Scroll down and click on Advanced Configuration.
3. Next, click on Message Booster.
4. In the Deafult Bidding section, select Optimize On + Pay For + Bid Amounts.
5. Save the Media Plan settings.
6. The final step is to boost your post again as normal within the Message Booster.

Note: Per Facebook's requirements, the budget that you select will depend on the number of ad sets and targets you have in your audience. For example, if an audience has 3 targets / ad sets and the desired budget is $5 per day, the budget you'll need to select will be 5 x 3 = $15 per day.