Maybe both your observation and HN is right: the distribution is multi-modal in the sense that (presumably) there is a large majority of people where the thumbnail works for and views the content, and then there is a small (and possibly vocal) minority of people who absolutely hate it and treat it as an anti-signal. I know I belong in the latter group and will lose all interest in the video once I see the weird face and the edited icon. I've seen a few of your videos and they're indeed very good. That said, I've noticed that I semi-consciously would avoid your video due to the icon which triggers an immediate reaction from me to stay away. It's a shame, because I know that the videos can be good, but the thumbnail is actively driving me away. In a way, I'm no different than the people who clicks on these videos, as I am also judging a book by its covers.
This kind of multi-modal behaviour can be very hard to capture with A/B test. You get a large influx of people that more than offsets the loss in the other audience pool. It's also anyone's guess on which group is better. From a pure business perspective, it's probably okay to lose me, as I use adblock and/or youtube-dl to watch the videos, which means I don't really drive revenue. That said, I've noticed some second order effects: as I'm more technical, I would recommend these type of content to others who will listen to my advice. I've noticed similar effects with others. If the more technical people are in the second group and are driven away, I wonder if this kind of stuff makes a difference with the long term health of a channel/content generator, which could be very difficult to quantify.
Like the sibling commenter here, reactions to this (as I've observed) are indeed very bimodal. If I see any video on YouTube with a face with a strong expression, I will not click it, no matter how interesting the title, because I hate how contrived the thumbnail is.
I think it might be more honest of you to phrase it not as: I have to do this because otherwise I don't get 20% more views. That feels a little bit disingenuous to me. You don't have to do anything. You could probably get a lot more views by colluding with another YouTuber to create drama or apparent "fights", like so many seem to. Aka, go full Kardashian. But you don't. You choose very explicitly what you do. Which does include goofy face thumbnails, but does not include staging YouTube drama.
A more honest phrasing to me might be something like: "Goofy faces get more views, and without them, my YouTube channel has much less income. I'm trying to support myself with YouTube, and so I am doing goofy faces even though I hate it and think it's completely asinine." You get really close to something like this phrasing, & the underlying message can be gathered by your other comments, but you don't outright own it. If you are going to do something asinine for exposure, you might as well own it imo.
So, with that out of the way: This project is really cool and thanks for doing a write-up & video on it :)
I just wanted to thank you for replying so candidly and I did not mean to turn this post in a discussion about youtube thumbnails, your post otherwise was quite interesting!
This kind of multi-modal behaviour can be very hard to capture with A/B test. You get a large influx of people that more than offsets the loss in the other audience pool. It's also anyone's guess on which group is better. From a pure business perspective, it's probably okay to lose me, as I use adblock and/or youtube-dl to watch the videos, which means I don't really drive revenue. That said, I've noticed some second order effects: as I'm more technical, I would recommend these type of content to others who will listen to my advice. I've noticed similar effects with others. If the more technical people are in the second group and are driven away, I wonder if this kind of stuff makes a difference with the long term health of a channel/content generator, which could be very difficult to quantify.
In any case thanks for your videos and insights.