To name but a few:
It all begins with the right targeting. If we don’t address the correct target group, it’s pointless. And even when we do have a good target group, we continuously monitor whether the message is being displayed to that target group. If there are discrepancies there, we modify the targeting.
It may also be the case that, based on specific data, one ad scores better than another. That’s the benefit of A/B testing. If one advert in a campaign converts significantly more often, we will focus more on that advert.
We also check what’s happening on the landing page. Are conversions being achieved? Are there leads coming in? Which advert is providing more leads? Where do people lose interest on the landing page?