Let's say you acquired 2x or 3x as many new customers in May 2020 as in May 2019, on the same marketing spend.
Clearly you enjoyed a COVID-bump.
Pay attention to downstream spend.
Follow the cohort by month, averaging how much is spent each month thereafter, and compare it to prior year cohorts.
For instance, you analyze your May 2020 newbies and you measure future spend.
- June 2020 = $9.00.
- July 2020 = $8.60.
- August 2020 = $10.25.
- September 2020 = $9.85.
- June 2020 = +31% vs. last year.
- July 2020 = +24% vs. last year.
- August 2020 = +9% vs. last year.
- September 2020 = +3% vs. last year.