There must be constantly changing user acquisition strategies for B2C startups and it must grow and evolve constantly. SEO,social media marketing,search engine marketing and all the other regular stuff from the book has almost never been the driver of growth.
Growth hacking (http://www.marketingmasala.com )strategies for startups come up everyday and you must ride the wave. Although,there are some tested methods that we have provided results for different types of businesses and startups.
Here is a detailed infographic that will guide you which channels to use for B2C user acquisition.