"Marketing" is such a broad term. It can encompass so many different things. IMO, all of the following constitute "marketing":
Advertising online or in glossy kiteboarding magazines.
Assembling a roster of talented pro riders who use and "pimp" your products at international competitions.
Assembling a roster of (often less talented, but highly personable) "ambassadors" who use/"pimp" your products at local beach.
Actively participating in forums like this one with marketing and building customer relationships as goals.
Staging demo days so potential customers can try your products.
Providing top notch customer service and support, including being responsive and helpful when things go wrong.
Personally, I think the customer service/support side of "marketing" is most effective and important. Epic Kites (Dimitri) is one of the best at this. (I have no affiliation with Epic and don't own Epic gear.) Epic's being a smaller company allows Dimitri to deliver that personalized service that develops brand loyalty. Service and support are keys to effective "marketing", IMHO.