Ask HN: How to actively find leads organically?

One of my friends has a small company (or agency?) specializing in web development & design, mobile apps development. The company has also developed SaaS-type software etc. He asked to find leads for him but he doesn't want to spend money on ads (and I being a PPC/SEM Consultant have devoted recent part of my work on paid traffic only). SEO-wise his website is okay but he is looking for clients from all over the world. He had international clients before, but a very minuscule number of them as compared to a lot of local clients.

How do I find leads for him? One idea I'm thinking is to participate in niche forums, engage in discussion and if someone is looking to outsource web dev, then I would offer my services (Is it ethical?). The other idea is to look for small or medium-size businesses who don't have a website or need a website redesign, contact them and offer my services.

But where to find such list of businesses with no website or poor websites. I have some idea about the local market but for other countries, I have no idea.

I have looked at freelance job boards and remote jobs websites, but most of the time they are looking for individual developers, not us.