Update: After 10 months of running one ad OttWatch made $15 from Adsense. Not worth it; killed.
I've decided to turn on one ad unit using Google Adsense, displayed in the top-right corner of the front page (or about half-way down when viewed on mobile). This is driven from curiousity about how much revenue the ad will bring in, not any serious attempt to make money. I already know it's going to make almost no money.
(Feel free to turn on your adblockers)
The front page gets around 50 views a day. Most visits to OttWatch arrive from Google searches on specific topics, destined for specific pages in the forest of information. Those visitors won't see the ad.
I've also placed it in a spot that shouldn't slow anything down. If you're on mobile you won't see the ad until you've already scrolled past half the content on the homepage, only your way to "recent comments" and the "feed". I doubt most people do that.