Yes, there's lots of talk about "passive income" but these days you really have to build value into a site, aka active income. It's a business like any other.
Nothing is really passive because the internet improves better non stop, and a "niche site" that might give you "passive income" for a few months or years can dry up very quickly after a Google update, an improvement in web standards, etc. So you always have to keep up. Rather than creating plenty of crap niche sites, I focus on 2 or 3 that I'm relly into it and that I know I'm able to watch and keep updated (in terms of content and technology) over the years.
Nothing is really passive because the internet improves better non stop, and a "niche site" that might give you "passive income" for a few months or years can dry up very quickly after a Google update, an improvement in web standards, etc. So you always have to keep up. Rather than creating plenty of crap niche sites, I focus on 2 or 3 that I'm relly into it and that I know I'm able to watch and keep updated (in terms of content and technology) over the years.