Don't imagine that social media will directly win you business. They might. Just like face-to-face networking might. But just as it's unlikely that you'll meet someone on day one who says: "Hoorah, you sell exactly what I need, let me give you my money", it's unlikely that a presence on Facebook, LinkedIn, Google+ or Twitter will automatically result in increased income.
Face-to-face networking works because of what you do and say in between your one-minute presentations and weekly or monthly meetings. Social media can work for profile-raising, SEO, inbound links, customer research in order to change your service offering, and monitoring mentions and sentiment.
If engagement is the key, then you have to be engaging. If you want to attract business, you have to be attractive. And if you want to charm people into buying, you have to be charming.
Perhaps surprisingly, one of the tweets that generated business for me recently was a link to a kids' game on the Innocent Drinks website, where you had to squeeze fruit into cartons (so it was a logical fit with the product but it was fun as well which is consistent with the brand personality). The phone rang, and the caller said: "Can you hear that music playing in the background?"
"Yes," I replied.
"Do you know what it is?" he asked.
"No," I said.
"It's the music to that Innocent Drinks game you just tweeted. Will you rewrite my website?"
Networking is not right for every sector, business or individual. It absolutely works if you do it right. But for some people, industries and brands, it's not a suitable route to market. Similarly, social media marketing is not compulsory or appropriate for everyone, but depending on your objective, it can absolutely work.
Tip: Before you start, be clear about why you're doing it and what you want to achieve, then measure the time you invest against what you get back.