Here are some simple tips when you're trying to decide what you should be optimizing for between unique open rate and unique clickthrough rate.
- If you're ONLY testing subject lines or main subject lines and secondary subject lines, chose Open Rate.
- If your variations are limited to what's in the message once a user opens it, choose Clickthrough Rate. That includes variations that have different layouts, graphics, CTAs, copy, colors, etc.
- If you're testing both subject lines AND body-level variations, you should probably default to Clickthrough Rate. This often a good choice if you don't time to run multiple experiments on that campaign step.
- Depending on what you're testing and personal preference it may make sense to actually separate out the subject line experiments from the body-level experiments. You can run one and then switch over to the other.