Yep! Social media is a great tool for digital marketing. And by advertising bitcoins you make more people invest in it, so in that way it has influence on bitcoin growth 
It is true that social media has big effect in terms of informing people to the real deal on having cryptocurreny or bitcoin itself. Because we all know bitcoin can serve as a good investment to all people because most of people shared their experiences on using bitcoin and dealing with this could encourage most of people to try having an investment to bitcoin or even having a transaction with the used of bitcoin for faster and reliable way of buying and selling.