Better safe than sorry.

I learnt Adsense Premium publishers can have their ads on a sticky sidebar.

So if you see a site with Adsense on their sticky sidebar, plus have more than the recommended 3 ads per page (some sites have more than 5), that’s probably an Adsense Premium publisher/site.

Provided he’s not an ordinary publisher unknowingly violating the Adsense TOS, follow their tactics, put your ads on a sticky sidebar and you’re sure to get banned.

Probably Chris is an Premium publisher. And maybe it doesn’t go against the TOS if you have other elements on the sidebar that scrolls with your page.

Still… better safe than sorry. You shouldn’t risk losing your Adsense account.