The short answer to that is: Facebook offers incredible value to advertisers. The truth is: It’s CRITICAL you understand the fundamentals of Facebook ads before you worry about split testing, CPC optimization, or other advanced strategies.
The most important thing is to find the right targeting for your audience. That means you have to do a thorough research of your potential customer`s interests. Additionally you have to combine it with e.g. the "behavior" or your customer.