With social media you have multiple options in terms of advertising, you can boost posts from your page’s wall, gain likes and circulate ads based on different objectives i.e. offering a sale, getting clicks to your site, ect.
The biggest benefit with social media is that you can collect leads more efficiently. Once they’ve subscribed to your page or opted into your newsletter your company can build a trustworthy relationship while continually marketing and gathering information about your target audience. With social media advertising you have the ability to very specifically define your target audience by factors such as age, gender, hobbies, interests and even by other pages/people they currently follow.
Advertising on social media is often more affordable then search networks, of course certain industries will have an advantage and gain more momentum from their social campaigns, for example pages about fitness, jewelry or cupcakes are going to perform better then pages about blinds, or trash pick up.