The niche that interested me the most, especially from listening to Podcasts, is Multi-Family.

Find something you do very first and make that your niche.

Get licensed, find a broker who does what you're looking to do, and then rock your niche!

Welcome to Bigger Pockets @Brandon Vannoy BP is loaded with all the information you will need to succeed in whatever niche of real estate investing you wish to pursue and the community is filled with knowledgeable investors and professionals to learn from and connect with.Listen to the podcast for extra inspiration and investing advice and post in the forum for any questions you have.

Find your niche where you can add value.

Find a niche and focus your efforts on marketing to that niche. 

I don't see a single positive besides being period correct if it's a Victorian mansion or something where the buyers would want an authentic period correct home (very small niche market).

Every platform has its uniqueness and serves different audiences depending on the factors like age, gender, demography, education, etc.

Large enough to support many different niches, but not too huge that it's crowded out.

It is all about the numbers, and some niches are better than others depending on the neighborhood.