Hey, been following your journey a while now, and it's had my white-greyhat ass jealous. I've been wondering if you've even setup your adsense units right.
You sound like you've had your turn around the IM block so I don't want to pretend to know more than you.
BUT, as a follower of the journey I want to help you push the envelope as far as you can go.
One of the easiest ways to increase CTR, and possibly also RPM is to add link ad units to the top of each post.
You can further increase the CTR by increasing the size of the link ad box. This increases the link ad units from 4 to 5, on mobile.
That's done by targeting the grid-ad-box with a simple css addition to your sites:
Code:
.grid-ad-box {
height: 180px;
}
I've seen an increase from 1% to 5% ctr by doing this. Of course, RPM can also improve, but that measure is always niche dependent. You can improve RPM by dropping categories, which I think you've tried.
The best way to optimize is to go from placement of units > to type of units > to color of units > to category of units.
I know people that only focus on RPM, but they started with huge levels of traffic.
It makes more sense to optimize ctr, because without ctr you don't get paid.
To all those worrying about running ads on sites with "little traffic" or doing this at all? Do you know how long it takes for a warning notice to be sent? NO? I'ts because you NEVER TRIED, SO SHUT THE FUCK UP.
If you want to see what ad placement/category is performing the best, then you need to install the publisher extension for chrome. Though, its kinda something you only would use if you run an authority site.
Don't ever use matched content, that speeds up fold notifications.