I am a Community Manager... not a Pony.
A Social Media Manager is someone who manages your presence on social media platforms such as Instagram, Facebook, Pinterest and Twitter. They will generate content calendars and moderation guidelines inline with the greater overall social media strategy for the brand. This person will need to be up to date with all the latest platform developments and on hand to advise the brand when conversation in the digital space requires action from either CS or PR. Their KPIs are provided but the Social Media Strategist who will define a goal for each platform for the brand.
A Social Media Strategist is someone who will look at your social media footprint, work with your sales/marketing team and create roads to common goals with can be implemented by the SMM.
They will have to be familiar with social media monitoring software and be able to analyse vast quantities of qualitative and quantitative data to generate a fully integrated plan of actions. They will also have the skill set to translate this information into an understandable plan for action for board members, account managers and clients.
As you can see, these are three very different roles. For every company, duties can vary depending on the brand, but the basics are all here. I often have to explain my role to people - most of the time it's recruiters trying to put me forward for a job that I'm quite often not interested in and most often not qualified for.
Social Media is important for any company that hopes to survive and grow in the next few years. If people aren't buying your biscuits I can damn well be sure their bitching about them on twitter and they'll tell you why. For service companies, using social media is key to understanding your users wants and needs. As for community, this is when you want to take your brand that step closer to your audience. This is where you want to create a kind of consumer that is a brand ambassador without handing over your hard earned cash. It takes time and you have to see it for the long term - it's not a quick fix. It can have many advantages but it is a brand by brand situation, speak to many people to find out what will suit you best.
PS. I am not a guru. If you call yourself a Social Media Guru you're a twat. If you are on the hunt for someone to help you with social media and you put Social Media Guru as the job title, you'll attract these twats. You'll also attract people who talk more that they do, yes they'll impress you with the latest SM news and the last article they read on Mashable but what have they actually done? The online digital industry is so new and continuously changing and evolving that calling yourself a Guru is pretty small minded. We're all learning... Even the experts!