The landscape has changed a bit since my post years ago, and @Cyberdevil is right in saying that ad revenue just isn't what it used to be.
I think this is actually a positive shift in the right direction... Ad revenue revenue is, even at it's prime, something that not only annoys the consumers of your content (who wants to watch ads??), it's only generating pennies (if that) per viewer. If you can build a following, and monetize that following directly (Patreon, for example), it just makes more sense... Instead of wasting everyone's time with ads, you're providing your fans additional value (In the form of Patreon benefits, etc) directly to your fans. If one person out of 1,000 really enjoys your content & decides to throw in a few dollars your way, you've already made as much as you would have with ads, and on top of that it's more sustainable.