How can I compare the performance of different discount campaigns to determine which ones are most effective?

To compare discount campaigns you will need to ensure that you track all the relevant KPIs. Some of these could include conversion rate, sales revenue, average order value, customer acquisition, customer retention, and ROI.

Compare the KPIs of the different discount campaigns and determine which has been performing best.

You should take note, that creating customer segmentations will help provide a better overview of the campaign's success. Some campaigns will work better with particular customers than others.

Once you have compared your results, you should run some A/B testing, where you make minor changes to the campaign to find what is the most efficient.