As with any B2B businesses, there are plenty of marketing channels that you could apply your marketing efforts towards.
However, since you’re in the B2B training field, then perhaps one of the best ways of getting exposure and leads with COLD traffic would be to build an online presence around training materials and content. Particularly if you’re in a specialist niche where your type of content isn’t very saturated online (it sounds like that’s the case!), then the medium-to-long-term rewards of such a strategy implemented correctly could put you head and shoulders above your competition.
As I assume you’re already the experts in what you teach, I’d imagine that creating high-quality content around your subject-matter should be a lot easier than for most businesses.
The content would be used as a foundation of all your marketing activities such as:
SEO – High-quality content (especially if coordinated with good content and SEO strategy) can yield great results at bringing your website to the top of search engines, particularly if you’re in a specialist niche.
Social Media – Every piece of content can be shared and promoted on social media to build brand awareness – LinkedIn can be powerful for B2B
Funnel Marketing – The content would act as top-of-funnel brand awareness, but it’s important to leverage a good lead generation process e.g. to capture emails and remarketing those interested customers at a later date.
To achieve the above it’s important to put in place a good foundation. The website should be built on a platform that can support a flexible content architecture that will grow over time and importantly you’d want this to integrate with a good CRM or email marketing tool.