It's not a secret that social media is very good for the search engine optimization... entire campaigns were run over social media with some degree of success. Social media congresses and meeting are kept all around the globe, and that's normal: humans are, by definition, social creatures. The internet is virtual, but it's no less social than the "real" world.
We do optimize websites for search engines using social media, so you can ask additional questions if you need more information. Meanwhile, there are some things you should know about how to make your web site more visible:
Have content on your website.
Optimizing a site without content is wasting money, time and energy on an action without results. People are coming for the content of your site: text, images, audio and video.
Find the audience (the target)
That means you must understand your public (you can consider the internet as a huge screen you must put information on and the visitor as an audience) and its behaviors, preferences, methods of publishing, and sharing.
Define your objectives
Objectives are often driven by marketing or sales, by the products and the services you offer, and the SEO applied to the web sites has long been directly accountable to substantial improvements in sales over internet. Social media is not direct marketing, so you have to apply different objectives and measurements. The role of SEO in a social media effort is to directly influence discovery of social communities or content via search. Indirectly the content from social media can boost links to website content, improving search traffic and online sales.
Establish a plan for your campaign
The plan for reaching objectives in a combined SEO and social media effort will often focus on content and interaction, since it is content that people discover and share. Whether a keyword-focused strategy for reaching goals means publishing new content or creating an opportunity for consumer-generated content, it must involve proactive promotion and easy sharing amongst members of the community.
Develop tactic for your campaign
As you might already know, some of the most used are twitter and facebook. Google tried something (they called it social network - it's social, of course, and it's almost a network) with Google Plus, but they are over the horizon from their main competitor - Facebook. They are not the only ones: Stumbleupon and Wikipedia, Reddit and Del.icio.us are great for improving the traffic on your site (and the list continue with a lot others), Flickr and Picasa are excellent for your images collections, Youtube for your videos.
The tactic for your campaign should consider as many elements as possible from the previous list. The success of the campaign is a mix of all of them, a social media marketing effort based on finding where the desired audience spends its time interacting with and sharing content. It's an investment in time and relationships, not just spamming some other web sites to promote your site.
Measure your goals
Trends over internet change all the times. Some time ago hi5 ruled, now there are the moments of glory for Twitter and Facebook (among others). Always keep yourself in touch with these trends and optimize your tactics to get the best results.
Measure your results
Ok. You've put your plans into action, you have done a part or all points you previously decided to do and now you want to know the results. Use the tools that show you the detailed statistics with the visitors on your page and where they come from. You can always learn some good things from that and you can optimize the future campaigns and the performance of your SEO.