My rule is that if I spend an hour a week (on average) using a source, they deserve a bit of money.

There's a videogame streamer I like. I probably watch 4-8 hours of her content, as she live translates Japanese games while playing them. At $5/mo, that is the cheapest source of entertainment available aside from used books.

For blogs I read once a blue moon, I don't typically contribute unless it's worth supporting.