I didn’t collect an email list when I built GreenExamAcademy.com or when I started SmartPassiveIncome.com in 2008. That was a huge mistake. It does cost money to build an email list, but it’s worth every penny. I recommend using ConvertKit for this. They have really good pricing, and you pay more as you grow. By far, it’s the best service out there. On SPI TV Ep. 28, I did a full ConvertKit demo you can check out if you’re interested! [Full Disclosure: I’m a compensated advisor and an affiliate for ConvertKit.]
The other option is to offer white label SEO services to web design agencies. What this means is they handle the web development side of things, and you take care of the search engine optimization work. The perk of this approach is you never have to deal with their clients. Most SEO consultants start here because all the client-finding work is already done. That leaves them to do what they're best at – ranking sites in Google.
In multi-level marketing programs, the sales force is rewarded not only for the sales they close but also for sales by people they’ve recruited to the program, though always beware pyramid schemes that are discugised as multi-level marketing programs. Generally speaking if recruitment and intiation fees are better paid/rewarded than sales it’s likely a pyriamid scheme.