Social media marketing for small businesses & startups usually starts with building a consistent presence on social media. Nearly three billion people (3,000,000,000!) use social media. By being present on social media & advertising on such platforms, you give your brand an opportunity to be discovered by your future customers.
Social media advertising platforms are so powerful nowadays that you can specify exactly who to display your ads to based on various different parameters such as User Interests, User Behaviours, Demographics, Geographics, Age Groups, etc. & not only limited to this but you can measure the user engagement with your business to predict user future needs and requirements for bringing up sales and cross sales to generate better ROI's.