You've done a good job of picking things that have large niche audiences and I'm sure that was entirely accidental. (blog.bulletproof.com)
With 20,000 daily users, 99Turkiye is buzzMedia's second - largest niche dating site. (datingadvice.com)
Do you homework, find out what subsets of larger niches exist that may be underserved, and determine if there is a market there to sustain e-commerce business growth. (selfstartr.com)