I do business strategy for startups through topographical business maps. It's the best strategy tool out there and helps avoid costly mistakes. It also aides in acquiring funding.
Could you talk a bit more about what services you offer? Do you have more of a consulting relationship or are you offering a service at a set price? Also, one random question: do you find most of your clients are from the UK? For some reason I've always associated Wardley maps with the UK but I'm not sure if that's actually the case.
2. No, US only. Wardley does originate in the UK. The US is slowly catching up. I predict this will be taught in college in 10 years.