I believe every marketer should have some side project, at some point, to keep their sword sharp - and maybe also remember why they got into marketing to start with.
I’ve had a few over the years, including:
Forgematic (SEO+PPC Agency) | 2021-2023
Forgematic (Newsletter) | 2020 - 2022
Awnavi (Boutique Marketing Agency) | 2014-2016