Media basics:
Commercial media exists to introduce buyers to sellers. The nature of the content used to attract the audience can be tailored to help define (or "profile") the interests of that audience (which could be your own customers). Crucially, if you are not a paying customer, then you are a product to be sold to advertisers. As users of notionally "free" services like Facebook and Google soon find out.
Social media:
There is a spectacular amount of nonsense spoken with great conviction about the significance of "social media". But much like daytime TV, it tends to attract a very specific type of consumer audience demographic of limited commercial value. Twitter is a much more interesting phenomenon, but the noise level is deafening. USP will show you the best way to make use of the opportunities.