Internet Marketing Digital_marketing_for_dummies | Page 333

Keep a common thread throughout your KPIs and have them measure related
metrics, such as add-to-cart rate and sales.
Calculating your test timeline
Every test needs a definitive stopping point. If you test into perpetuity, you ignore the
possibility that no change occurs between variants. You need to create a clearly defined test
time period before you start testing, and then stick to that time table.
Use your duration calculator, mentioned in the “Obtaining the tools you need to run split
tests” section, earlier in this chapter, and round up to the next week. For example, if your
duration calculator says that you would have meaningful results in ten days, run the test for
fourteen. People behave differently on different days, and you must account for this
variance in behavior. This little trick will help you gather more complete data.