Some good examples of startups that were boosted by social media are:
-Yelp: Yelp is a website and app that allows users to rate and review local businesses. It was one of the first companies to really capitalize on the power of social media, using platforms like Twitter and Facebook to spread the word about their product.
-Airbnb: Airbnb is a website and app that allows people to rent out their homes or apartments to travelers. They too capitalized on the power of social media, using platforms like Instagram and Snapchat to reach a wider audience.
-Upworthy: Upworthy is a website that curates and creates shareable, feel-good content. They were one of the first companies to really understand how to virally market their content on social media, and as a result, they've been extremely successful.