What I was talking about was buying ad spots in other people's newsletter. I haven't done it myself, but have heard of others having a lot of success.
My advice would be to find some top blogs in your niche, then see if they list that option on their advertising page. If not, then contact them directly to see if they'd be willing to let you advertise to their list or buy advertising space in their newsletter.
This is a new marketing technique for me, I'll do some research on this. Maybe apply it later. Thank you.