Facebook ettiquette and marketing your business

So you found social media and think it's the one miracle cure for your business woes, All you have to do is join all the local groups and tell them about your business. They will then come flocking to your doors and throw money at you. This seems to be the consensus amongst all the social media gurus and what not.
Social media gurus sell snake water, religion and homeopathy or in simple terms bull manure. I have been on social media since the early days and I have done many deals directly attributed to my social media presence in the last 5 years. I have had lots of enquiries with nary a response to my response. Here is the thing, saying how much is so easy, whether you care or not.
I run a few groups and the social media gurus sell their services to clients in my town and they come and spam my groups, leading to a banning and the worst of it both groups are there for businesses to use for making themselves known. There are a few simple rules, don't spam and add value is the major criteria for belonging to these groups. When I go through the group and see exactly the same post on three or four posts down, I know you have not read the rules, you are a total idiot, arrogant and selfish. 
You add no value, you care about one thing and are probably desperate because everyone is ignoring you. Here are a few simple tips, If you make things, post a pic and tell us about the product, tomorrow discuss a new one. If you sell a service ie wedding planning etc. Tell us about wedding dresses and those that are interested will read the articles, or a photographer, talk about the difficulties of achieving the perfectly lit shot when you have 3 shades of white on the dress and a pale bride. Tomorrow talk about shooting the perfect pic with bad weather, don't just put up a digital flyer over and over. It's pretty annoying and I know I will never use your services because you spammed my groups.
I get my best responses from social media when I offer value, something unique and fun. 
Facebook is not going to save your business if you are in the doldrums, neither will twitter or any other social network. The gurus are lying because they want your money. I track all my advertising religiously. My website gives me some results, my social media some more, but the real results come from me doing the hard work that is needed to make stuff work, getting seen and known is where it's at. MY dad always taught me that running a business without advertising is like winking at a girl in the dark. Only you are aware. Further he taught me that spending money on advertising that get's no results is folly. 
When you advertise, make sure you know where your results come from, and spend more right there. If you are advertising in the local paper and your return on investment is not profitable stop. How do you define return on investment. If you get enough work to pay for your advertising and not much more you are not winning. Try something else.