SEO = Search Engine Optimization; It is the process of ensuring your website is on top of its industry keywords.
PPC = Pay Per Click Campaign; This is the process of ensuring your website is on top of its industry keywords for the Sponsored Advertising modules located on top of the organic sections.
Social Media = Ensuring your online presence is standard in all Social Medias such as Facebook, Twitter, Tripadvisor, Yelp, Google Maps, Google+, etc.
Developing your online presence with these aspects in mind, working in combination, is possibly the single best thing you can do to automatically increase your new customer base.