You don’t have to buy it online, just raising awareness or influencing an offline purchase are also goals for online advertisements. Across large groups it can

You don’t have to buy it online, just raising awareness or influencing an offline purchase are also goals for online advertisements. Across large groups it can approach being more formulaic where FB et al. will show you predicted # of conversions based on your inputs before you start a campaign. Of course you are trusting their estimation process then.