You must work in a creative industry and have a decent business network.
Promoly is for those needing to promote audio content over email, so you must take that into consideration.
Working in the promotion space isn’t essential, but a close business interest is recommended. Such as; a mastering service. Those who need their music mastered will most likely be record labels and music producers. Those record labels and producers will also need to promote their release, so that is an opportunity to tell people about Promoly.
Another good example is a music distribution company, drum & bass blog or perhaps a graphic design service.
If your business is similar and non-competitive, you’re a good fit.