Try Email lists and giving free content that's high quality.
For example I'm reviewing Language Learning Software for people interested in Mandarin. I'm teaching beginner's classes on my website free. Also, I'm providing information on various "little-known tourist spots" in China. The point of the ladder is so that once they know or are learning it with software, they might decide to travel to China and remember to stop by and maybe even just when they hear someone they know wants to travel there they can refer them.

I hope this helps, message me if you need any more advice.