That sounds like an interesting strategy. What niche did you end up on? I'm still a young developer so I have time/patience to try new stuff, but I'd love to focus on a niche someday.
Ruby/Rails/PostgreSQL, rendering on the server as much as possible, jQuery for client-side stuff as much as possible. I occasionally niche down even further to Stripe integrations within that sphere, but there's not as much work there as I would have hoped.