Facebook adv is so cheap compare to Google Ads. If you able to bring traffic from facebook then why not go for it? Unless your business are not suitable to promote in facebook . Facebook adv able to customize by country, state, demographic such as age, male or female, occupation , education and so on . This help you bring to the nearest target traffic that you want. Beside that you able to choose you would like to have cpc and cpm. It also a good social media network to build brand awareness and brand name as well.
I have run facebook adv for a while but so far unlucky. many people said with fb you can get niche laser market/buyer but in fact you must try many time 'till get most effective adv. so I think this is longtime journey
Ofcourse it is a great idea, only if you implement it properly with plan. If you know exactly what you are targeting for in Facebook advertising, you will get 100% return out of it. However make sure you have some kind of plan, to target small amount of traffic/people first and then you can eventually expand your search. There are millions of users as well as billions of viewers roaming around on Facebook 24/7, by doing the advertising you will get atleast half percent of the eyeballs if your sales pitch is attractive Hope this helps !!!