Everything has a niche if you just keep looking for it on the Internet. I love finding little groups, even if I don’t have an interest in them personally. It’s just so great to find them existing.
Today I found: Flickr: Ice Hockey Photographers Association
What niche could you be working on? Something interesting to yourself and a group of 2 or 3 people at most? The odd thing about these micro niche topics is how they grow. You start with one person, other than yourself and think that’s nice. But, once people begin to find your niche it just grows and grows.
I began my own niche group on Flickr (years ago). I didn’t do a lot to promote it and there was no SEO involved as far as anything I did. But, my group has over 600 members. Sure some will be forgotten accounts and so on. But, even half that many members is quite amazing for a little niche.
Pick a niche of your own and try it. Put up a free site to start with, post about it on social media and begin making posts to the site. Add photos, add ideas, etc. You might be pleasantly surprised.