Yes, there are solo ads and solo ad suppliers for every niche imaginable, but…having said that, I still recommend you focus on the ‘make money’ category, especially online.
Why (I hear you ask!!)? Because there’s just so many people actively looking for that information — it truly is that ‘starving market’ we hope to have with any product. There’s plenty of opportunity for us to quickly hop in and sell clicks to people that want to give us their advertising money, and plenty of people eager to click the links we send out.
So other markets and niches will definitely work (as Coach says, if there’s a magazine for it, there’s a market for it. That’s a quick way to tell!), but this one has so little resistance to buying, just literally walk in and sell what they want, that it makes it a true ‘no-brainer’, at least to start with.
Hope that helps!