Mailman – Find email newsletters you can sponsor to promote your product/service
hellomailman.com
hellomailman.com
(the "mailman" part is probably the wrong thing for branding, anyway -- I'd pick branding focused on the sponsor/trust/endorsement/patron aspect, so you can extend to other channels like video. You should decide if you're selling single branded links or (limited duration?) sponsorship.
If it's a sponsorship marketplace, the value is a lot higher to both sides -- if there were a great "devops security bulletins" newsletter or alert list, it would easily be worth $10-20k/mo for a remediation vendor, platform vendor, or specialist recruiter to sponsor it, and you'd get a larger amount of money than selling a bunch of $100 links. There are probably thousands of valuable niches out there.)
However, I do look forward to seeing where this project goes.
It makes sense, but I was expecting you to basically be the broker that takes a cut on the ad buy side from potential sponsors instead.
* Hyper-local newsletter for developers in Indianapolis: http://www.indyhackers.org/We have a rebrand in the works, however, as due to our reluctance to heavily promote or send arbitrary emails to subscribers, we have a lot of subscribers who don't know about the other publications.. and our stable is not very cohesive branding wise. This will be resolved by the end of the year :-)
Scroll back over Hacker News over a few months and you can spot the moment when people caught on that putting "Machine Learning" in their titles got clicks, regardless of how valid that was.
"$TECH weekly" is a similar level of branding to all those lists of projects which are "curated". Seriously search past submissions for "A curated list of ..". They're cookie-cutter posts that could probably be generated by machine-learning!
As a NL owner with 8k subs, I would recommend offering a test plan of some kind.
(My list, by the way, is also not not dev-related—which might help you branch out your offerings some.)
Obviously, needs more than developer-focused mailing lists.
Is there a way you can link to the source of your information regarding the List Size, Average Clicks and Sponsor Rate?