I'm no expert on this area, but from what I've seen ad revenues are nowhere near high enough to pay for decent journalism. If they were we wouldn't have the pay-wall debate.

Affiliate links tend to be a huge no-no because of conflicts of interest.

Publications generally only buy articles if they have first right of publication.

Suggesting someone can earn 30K-70K on the above basis seems over-optimistic to the point of being misleading.