A business owner told me he has decent traffic to his website, but no conversion. This could be one of the factors. In short, we want the most relevant and effective target audience.
The answer to that is pretty simple. Within targeting, go to 'behavior' > 'digital activities' > 'Facebook page admin'. The idea is if you are a business owner or manager level, and you are on Facebook (and of course believing in digital marketing), you would probably own a Facebook page or managing your company Facebook page.
Aside from that, there is also 'behavior' as 'small business owner' that is more direct. However, I'm curious how Facebook would segment its audience to that group.
Regardless, the best practice for successful Facebook ads is to test, test & test. Thus, run a few campaigns with different targeting and build your own most effective targeting audience.