[rainbowmverse]

I always appreciate one-off sales/donations, but they aren't really dependable the way a subscription is. You can't plan or invest around it unless the thing you make is the kind of thing that gets a hobby/business-sustaining amount of sales or donations.

A sale/donations says "this is cool." A subscription says "I want to see more of this." For the former, there are sites that popped up and got better established while flattr was twiddling its thumbs for 7 years. If I were going to ask for donations, I'd post a ko-fi link or a bitcoin address, not ask people to install an extension.

[detaro]

It's automatic distribution (with the option to also trigger one explicitly if you want). I and many other of your visitors are just about as unlikely to donate to you as to subscribe (well, in my case even more unlikely, since I can't think of any comfortable one-time donation thing I use), so if we use Flattr you can choose to get a piece of our collective pool or nothing from us. Time will tell if it's worth it, but I don't think the framing as an alternative makes sense. None of the things currently in use do the same (except Brave, I haven't kept up what they are doing exactly).