If you want to increase or decrease bid ranges, simply add bidtest[__%] at the end of your ad set name. For example, if you want to double the bid range, use bidtest[100%]. If you want to increase it 50%, use bidtest[50%]. If you want to decrease the bid range, you can make the % negative (e.g.: bidtest[-50%]).
You’ll likely be re-bidtesting an existing source ad set, so make sure to first delete the --’s on your ad set name and everything to the left and the right.
For example, an existing source ad set will look something like this:
C → -- 1% Look-a-Like bidtest -- running
To re-bidtest and increase the bid range by 50%, it would be changed to:
1% Look-a-Like bidtest[50%]
If you are increasing bid ranges to counter auction demand pressure, we highly recommend that you pay close attention because if demand does drops, you will likely get a lot of delivery very quickly.