Ask HN: Channels for growing a data science consultancy

Three years ago my partners and I founded a data science consultancy (see www.vertexintelligence.com), which has grown organically through our networks in the local tech scene in Indianapolis. We're hoping to expand beyond the midwest and want to avoid spamming/cold calling. I've found that paid search is not very effective, and content marketing only goes so far. Does anyone have any tips that have worked well for growing similar highly technical consulting businesses?