Facebook provides three advantages to any person who wants to launch his business :

Huge Market
As of the fourth quarter of 2018, Facebook had 2.32 billion monthly active users in the world, that means there is a considerable chance that your prospect is using Facebook.

Specific targeting
Facebook targeting options are incredibly powerful; you can create an audience based on the level of education, hobbies and other criteria based on their behavior.
This powerful targeting means that you are less likely to waste your money by targeting the wrong people.

Quick results and easy to measure
The fact that you can quickly get specific results whether it’s good or bad, make it an almost risk-free communication channel.
For example, if you’ve invested 10€, you can see in real time how much it makes in revenue or you many people you’ve reached.

The key point of Facebook Ads is its Return on Investment and its accessibility.

 

Indeed, it’s easy to launch a campaign on Facebook, for example, you can start with a small budget to test different CAMPAIGNS and AUDIENCES and then analyze the results :

If an ad drives more revenue than it costs, it’s easy to increase the budget

and in the other hand 

If an ad drives less revenue than it costs, it’s easy to stop or modify the campaign.