Fb PVA account is the most effective platform to promote your business. Here one thing I must mention is Facebook is not only a place where you can promote your business but also a platform where you can establish your business as well.
You can use Facebook as per your need or motive. If you want to promote your business and want to reach to a massive number of customers, you can buy FB accounts and post advertisements for your brand or product. Or else, you have another option as well. In case you want to establish your business on Facebook, you have to buy real Facebook accounts and create your business page or you can establish a group where you can sell your products.