I have got one notification from Facebook that they have updated his advertising guidelines for dating, matrimonial and apps related ads. Now they will have to got ads partnership certificate from Facebook to promote his page. If you want to get the certificate than apply for Facebook partnership from 15 Feb'14.
Facebook is a popular social networking site and part of the internet marketing nowadays. It can be used for promotional purposes, because it can really helps to improve your website's presence, thus, additional traffic. I've also read some article that twitter and facebook can now affect search engine rankings. I'm still a bit confused about it, but as per my opinion it really helps in SEO work.
I agree with you that in Social Media Sites 'Facebook' have great reputation and peoples are moving on facebook too much rapidly for the business and putting the ads there for advertise the business. Facebook are updating the websites with alot of applications. I don't think so that there is any website which will beat to Facebook.