I've found myself in a particular situation where I have a website for a non-profit organisation.
I'm getting requests from third parties who would like to guest post and advertise on my website. Though i'm okay with their requests, i find it hard to define a pricing model for advertising.
The website has about 200k annual visits, but it's still growing. Domain authority is about 41.
Do you guys know whether there are any models that can help me determine a proper ad pricing scheme?