Depends what industry you're in as to whether it is the best way to target your market. Facebook is great for credibility (no matter who you are) and reaching consumers but can be less effective for business to business.
Also it's important to have a good plan to increase your followers and fans.
The best thing about these ads is the ability to target your exact audience. Eg i want this ad to be show to anyone in the uk thats female, whose birthday it is, and is under 30. No other platform offers this.