Facebook is one of the most popular social network in the world and it is one of the best and cost effective way to advertise a product online. But you should not expect a 100% success. The return of your investments still depends on the way you display your slogans, images and the quality of your services & products. Facebook can help you with the things you might require as you choose your target market and audience. But, it cannot guarantee 100% success in your advertising.
Having a website is one of the best way to promote your products as well as services on the web because a website a be accessible from any part of the globe. You can make your website popular via doing SEO for it.