Facebook Ads: How narrow should my ads audience be?

[Mossy]

If I'm targeting my ads to those interested in other authors in my genre, should I be creating separate campaigns for each targeted interest, or one campaign that includes all those interests?

I try researching this on my own, but it's difficult finding anything relevant to book advertising, which I feel is much different than what I'll find being suggested for other industries as far as facebook ads go.

Thank you guys for any suggestions you might have.

[Lu Kudzoza]

I start with a very targeted audience. One or two authors that are very close to the style of the book. Then when the audience gets exhausted I add more authors. Basically, start with the closest match then expand further from your sub-genre to the wider genre authors.