Totally fair question - Most of it started as word of mouth - as sales happen your rank rises in the Amazon search category - there are also some simple things

Totally fair question - Most of it started as word of mouth - as sales happen your rank rises in the Amazon search category - there are also some simple things you can do on amazon pretty cheaply (run ads on keywords, make sure your listing has solid photos and I think in general doing FBA is smart because it makes your listing prime eligible)