You can divide audiences into two groups: prospecting and retargeting.
- Interests: use the Facebook Graph to target people by common interests related to your brand.
- Lookalike: people similar to your current customer.
- Customers: a custom audience with your existing customers.
- Visitors: a custom audience with people who visited your site.
Prospecting audiences are those you can create with the out of the box tool in the Ads Manager. My recommendation is that you focus more on the psychographics of your group, that is the interests they share in common, rather than demographics (age, gender, etc.)
The cost of reaching people is usually low, but don’t get confused about it, the cost to acquire a customer will be higher because the prospecting group doesn’t know your brand yet.
In the same prospecting group, you can create a custom audience. If you already have a customers list, you can use it to build a lookalike audience (people who are similar to your customers.)
The retargeting group is where you have more chances to get a conversion at a lower price. Reaching a retargeting group is usually more expensive, but the conversion cost is lower.
You have two options here: either you create a custom audience with your current customers and use it in an upsell campaign, or you can create an audience of people who visited your site and retarget them to come back.