I love what Pieter's doing! There may not be a business model at the moment, but getting these products out of the door is a first step. After 12 months, he'll have a good idea of which ideas work, which don't, and what to pursue next. Good luck!
You can say that lessons learned from launching 12 sites will help pivot into one that works as a business, but that's one company with 12 products, not 12 companies.
For one, ads are not a bad idea. Startups are not just for $5 billion buyouts -- they can also be $500/month side projets.
Second, he already said he has an idea about selling guides for how to setup business in each of those places.