Write down a hypothesis before launching
Specify exactly what is changing, for whom and what result is expected. Prepare materials with the same current offer. If you're testing an argument, don't change price and geography at the same time. Real photos and confirmed conditions are more important than decorative design.
Continue with: Advertising landing pages: a pre-launch checklist.
Define the evaluation conditions
Agree on the budget, period, and events for which you are comparing options. Consider the sales cycle and data sufficiency. The distribution of impressions in a normal campaign is not necessarily equal; for a controlled comparison, check the available experiments tool and its terms in the account.
Continue with: Facebook and Instagram leads: assess quality, not just cost.
Make decisions based on the business outcome
CTR shows the response to the ad, but not the quality of the lead. Compare spend, enquiries, qualified leads, and sales against an agreed upon attribution rule. Write the conclusion and the following hypothesis. An indeterminate result is also useful: it means that there is not enough data or difference to make a confident decision.
Can we announce a winner for the first day?
Sometimes a clear technical problem is visible, but the conclusion about effectiveness depends on the amount of data and the sales cycle. The calendar day itself is not a criterion.