I have friends that recommended me to people looking for what I offer, but they all contacted me directly. In my case, none of them were interested in creating a Fiverr account and paying a fee to get an order we could have directly discussed face to face.
It seems my experience is different from yours, and sharing on social media definitely could help you landing some customers, but if you're a newbie that has spelling mistakes all over your gigs and have unattractive gig videos/ images, you probably won't get new customers even by sharing on social media.
Most of the people that do share on social media, are usually sellers that still haven't received a single order yet, or have only a couple of reviews on their profiles. The majority of the experienced sellers on the forum say that sharing on social media is a waste of time compared to other things you could do in your free time, like optimizing your gigs and your skills, or even read books about business growth, etc.
You're actually the first person I meet on the forum that was able to land some orders through social media, and I'm happy for you, but I don't think social media promotion should be one of the first tips to give newbies, as it works only in particular cases.