That revenue is about 50/50 from Adsense and subscriptions. I made the site freemium in May and subscriptions have become the majority of the revenue the last couple of months. It's currently doing about $1,400/month -- ~$900 from subscriptions and the rest from ads.
http://projects.lukehaas.me/css-loaders/ http://projects.lukehaas.me/scrollify/
$450 Released this month though.
But hey, it's not even close to being done.