Can I promote my website just with social media?
 

Websites and brands can be promoted with many different tools, but social medias have proven to be the most effective of them in the past few years: you get in close touch with users, they're less invasive and they're generally more effective at redirecting traffic.
Given this, if I were to promote my website, could I rely on social networks only? Buying ads for a personal website seems like a waste, and I feel like affiliate marketing wouldn't work too well in the early stages.