PPC will likely be your least effective channel to acquire customers in the long run. My recommendation is to start with exactly who your buyers are and then imagine yourself in their shoes, where would you go to find info. on a company like yours? Who would you trust? What channels (search, email, social, etc.) would you prefer and be most likely to engage with a company like yours? Then brainstorm every possible channel (events, networking, PR, LinkedIN, partners, etc.) that you could use and then prioritize those based on (reach, cost, time to acquire, effort) and then test (via pilot programs) the top 3-5 channels (i.e. Facebook ads, attending events, writing a guest blog post, offering a webinar) and see which ones are most effective (i.e. bring in customers with a low CAC - customer acquisition cost).
Typically, I see organic search and referrals as the biggest sources of traffic. But organic search (SEO) takes 3 months to make an impact in rankings and referrals can take many forms (IRL word or mouth - best, or social referrals).
Hope this helps. Happy to provide more insights. Just schedule a call with me.