It's going to be $3 for an entire 30 days
I dunno, $3.00 a month seems high to me, if that would be for a single site, for the whole program, probably not bad.
I subscribe to 20+ print magazines. I pay less than a dollar a month for most of those. A couple of the very highest quality content cost up to $4.50 a month, but those are exceptionally (in my opinion). I know of a couple other print magazines in the same niche that run in the $10.00+ per month, but frankly the difference between them and the others is the lack of ads. Would I pay an additional 5 - 6 dollars a month to avoid the ads, no.
I'm thinking this could affect traffic for some sites, especially if Google labels the participating sites in the serps like "Ad Free".
But those people probably aren't going to click and ad on my site anyhow, so is that loss of traffic a real loss?
Now if the give thos participating sites a boost in the rankings, that could make a difference.
Add in "Mobile Friendly" and it could add up. "Ad Free + Mobile Friendly"
Me, I like related ads on sites I visit and on my site, so no, I'm not signing up for this.