A bit of punctuation would help here. Are you asking which is better — word of mouth or social media? Or what's the best way to attract with both methods?

You need a mix of marketing. The best approach is to target and attract your best type of customer, rather than chase them down. WOM and social media can be used for both methods. In both cases you need to identify who you serve and show up where they show up. I've found clients in LinkedIn groups, and at face-to-face networking events, service club meetings, recommendations from current clients, and such.

So, who do you serve? How do you help them? How will your product or service transform their lives? Research where these folk hang out online and in person, and go there.