Deeply niched means getting as exotic and specific as you can with your keywords and your selling.

Bears are not too deeply niched - they are niched a bit more deeply than just general gay, or gay hardcore, but to take the niche deeper I might have chosen "muscle bears", or "mature bears", or "leather bears" - as possible examples.

"Leather bears interracial" would be even more deeply niched.

The idea is, there's less competition for keywords the deeper you niche. There's also less traffic typically. So it's a kind of tradeoff.

Personally, I always thought "sell what you know" is one of the best strategies, and one could make the argument that it's just as good a plan as going deeply niched.

Ooops, bec had already answered - anyway, thats what it means.