As much as I dislike Facebook and cannot stand Twitter, the value of those two social media sites to businesses is extremely high. It is an inexpensive way to market things like deals, specials, etc... Businesses don't usually have people who are knowledgeable enough about social media to really take advantage of those sites. So, they hire social media consultants. It is very possible that some of those consultants are just unemployed high school dropouts who spend 24 hours a day on the computer. However, you cannot deny the value of the sites and there are people who are actually very good at dramatically increasing "followers" or "group members" or whatever. There are actually techniques that social media experts use.
This question is kind of like asking "What the hell is an SEO
consultant?" There are going to be people who claim to be SEO
experts, but are not and they sell themselves as consultants. However, I don't think anyone with even basic knowledge of internet business can dispute how important SEO
is, and there are people who have spent a long time researching it, testing different methods, etc... It's just that social media is relatively new to businesses so it isn't yet as accepted by the general population as SEO
is. Plus, there hasn't really been enough time to weed out the "fly-by-night" operations.
In any service industry there are going to be people that claim to be part of the industry that have no idea what they are doing especially when the industry is pretty much unregulated.